delivered the opinion of the court:
In January 1995, plaintiff, Dennis Clemons, filed a complaint against defendant, Mechanical Devices, Company (Mechanical), alleging that Mechanical had wrongfully discharged him in retaliation for his filing a workers’ compensation claim. In October 1996, a jury returned a verdict for Clemons and against Mechanical and awarded him compensatory damages of $63,520.23.
Mechanical appeals, arguing that the trial court erred by (1) admitting evidence regarding the Illinois Wage Payment and Collection Act (Wage Act) (820 ILCS 115/1 et seq. (West 1994)) and instructing the jury on portions of that act; (2) allowing a lay witness to interpret statutory law; (3) allowing Clemons to amend his complaint following the close of evidence; (4) denying Mechanical’s motion for judgment on the grounds of res judicata', (5) denying Mechanical an opportunity to cross-examine Clemons as to his testimony at an administrative hearing; (6) refusing to allow a witness to testify regarding payments made by Clemons’ health insurance company; (7) refusing to give Mechanical’s nonpattern jury instruction defining "at will” employment to the jury; and (8) allowing the jury to consider emotional distress as an element of damages. Mechanical also argues that the verdict was against the manifest weight of the evidence.
Because we agree with Mechanical’s first argument — namely, that the trial court erred by admitting evidence regarding the Wage Act and instructing the jury on portions of that act — we reverse and remand for a new trial.
I. BACKGROUND
In January 1995, Clemons filed a complaint against Mechanical, alleging that Mechanical had wrongfully discharged him in retaliation for his filing a workers’ compensation claim. This case was tried before a jury during September and October 1996, and the evidence showed the following. Mechanical, located in Bloomington, Illinois, did design, engineering, and machine shop work.
*245In August 1988, Clemons began working at Mechanical as a machine operator. He told Mechanical’s staff that he had previously had back surgery. On June 1, 1989, Clemons injured his back at work while lifting machine parts. He reported the injury to his foreman, Clarence Hatfield, and the following day (at the direction of Irene Sperry, a co-owner of Mechanical), he saw Dr. Larry Nord, who prescribed pain medication. Although Nord advised Clemons not to return to work, he did so that same day and worked the rest of June without further injury. Mechanical’s workers’ compensation carrier processed and paid the bills incurred as a result of the June 1989 injury.
On July 1, 1989, Clemons heard his back "pop” while he was working, yet he worked the remainder of his shift. Upon leaving work that day, he told Hatfield that his back was "still bothering” him and he was going to take it easy over the weekend. Hatfield testified that he recalled Clemons reporting the June 1989 incident; however, he did not recall Clemons reporting an injury on July 1, 1989. Linda Fillingham, Mechanical’s office manager, testified that she did not receive notice on July 1, 1989, that Clemons injured himself. Clemons testified that he stayed flat on his back "the whole weekend,” and his back pain was in the same place as it was after the June 1989 injury.
On Monday, July 3, 1989, Clemons’ back "popped” while he was bending over to tie his shoes at home. He telephoned Fillingham and told her that he was not coming to work because he hurt his back while tying his shoes. Fillingham told him that she would send him a health insurance form to complete. Clemons testified that he had a conversation with Irene, who told him that she "knew this [(the July 1989 injury)] was not workmen’s comp[ensation] and if [he] filed it that way, [he] would be discharged.” Clemons also stated that he believed Irene because "she doesn’t say anything without meaning it.” At some point after speaking with Irene, Clemons (with his wife’s assistance) completed the health insurance form, signed it, and returned it to Mechanical. The form, as filled out by Clemons and his wife on July 13, 1989, indicated that the July 1989 injury was not work related.
Clemons also stated that someone from Mechanical called Nord’s office and told Nord’s secretary not to file the July 1989 injury as a workers’ compensation claim. Fillingham acknowledged that she had a telephone conversation with Nord on July 10, 1989, during which she told him to keep his records straight between the June 1989 injury (which was being processed as a workers’ compensation claim) and the July 1989 injury (which was being processed by Mechanical’s health insurance company).
*246Clemons’ wife, Janetta, testified that on July 3, 1989, she heard "a loud pop” from Clemons’ back as he was preparing to go to work. Later that same day (after Clemons spoke with Fillingham), they received a telephone call from Irene. When Janetta told Irene that Clemons was not available, Irene said that she did not like "to get the wives.involved in things like this” and hung up.
Clemons returned to work on Thursday, July 27,1989. He worked that day and Friday, July 28, 1989. He previously had elected to take the next week (July 29, 1989, through August 4, 1989) as a vacation week.
On August 2, 1989, Clemons talked with an attorney, Kevin Miller, at the Janssen Law Center (Janssen). On that same day, Clemons signed a blank workers’ compensation application in Miller’s office. Miller testified that he telephoned Mechanical that same day and asked the identity of the company’s workers’ compensation carrier. Someone at Mechanical told him that such a request must be submitted in writing. Janssen’s subpoenaed telephone records did not show that Miller made a telephone call to Mechanical. However, Miller stated that all of the telephone records may not have been produced. Miller also stated that Clemons was hesitant to file a workers’ compensation claim; nonetheless, Miller proceeded with the claim on August 2, 1989.
On August 4, 1989, Clemons went to Mechanical and told them that he wanted his paycheck for Thursday, July 27, 1989, and Friday, July 28, 1989. He was told that he would be paid for those two days on August 11, 1989, in the following week’s regular check, thus making a full week’s check. This was the same way vacation had been paid to all Mechanical employees for previous vacation periods. Mechanical paid its employees on Fridays for the previous Thursday through Wednesday pay period and paid them for vacations one week in advance. Miller called and told someone at Mechanical that they could not hold the two days’ pay. Fillingham told Miller that Clemons could receive a paycheck for those days, but if he took his pay in a manner different from all other employees, he would no longer be employed by Mechanical. Fillingham also testified that Clemons quit when he chose to be paid differently from all other employees and he was not fired because he retained an attorney to file a workers’ compensation claim.
Barb Gullett, Nord’s receptionist, testified that when Clemons came to Nord’s office for the June 1989 injury, he filled out a workers’ compensation patient questionnaire. The first bill sent out by Nord’s office had a "WC” (workers’ compensation) designation. A bill dated July 27, 1989, also contained a "WC” designation, but Gullett *247had crossed through that entry and written "personal injury 7-3-89.” Gullett stated that Nord gave her that information. Prior to the July 10, 1989, telephone call with Fillingham, all of Nord’s records contained a "WC” designation. After the phone conversation, all of the records relating to the July 1989 injury were changed to reflect a personal injury designation.
On August 8, 1989, Mechanical received an application for adjustment of claim stating that the July 1989 injury was work related. At that time, Fillingham put the health insurance forms on hold until she could determine whether the injury was work related. She also stated that she voided some of the health insurance checks and sent letters to health providers indicating that Mechanical would not pay any health-related medical bills. In her testimony during Mechanical’s case in chief, Fillingham stated that she had incorrectly testified that Mechanical had paid none of Clemons’ health-related medical bills because she previously did not have access to all of the pertinent records. She further stated that when Clemons submitted bills to Mechanical for the July 1989 injury, Mechanical’s health plan paid them (except for Clemons’ deductible and co-pay portions). Mechanical did not pay other medical bills which were not submitted to it.
After the Industrial Commission denied his workers’ compensation claim for the July 1989 injury, Clemons resubmitted his bills to Mechanical’s health insurance provider. According to Clemons, Mechanical never submitted the bills to its health insurance company.
Randy Griffin, a former Mechanical employee, testified that he sustained a hernia while lifting a block at work. He reported his injury to Mechanical, and it instructed him to complete a health insurance form. Fillingham subsequently requested that he write a statement that his injury did not occur at work. Griffin refused to do so because he believed it happened at work. Griffin stated that he never had any intention of filing a workers’ compensation claim; however, he did not want to write the requested statement. That same day, Irene told him he was no longer needed as an employee.
On this evidence, the jury returned a verdict for Clemons and against Mechanical and awarded him compensatory damages of $63,520.23.
II. RELEVANCE OF THE WAGE ACT
Mechanical first argues that the trial court erred by admitting evidence regarding the Wage Act and instructing the jury on portions of that act. Specifically, Mechanical contends the Wage Act was irrelevant to the issues in this case. In response, Clemons argues that *248evidence regarding the Wage Act was relevant, not because he based his claim upon a violation of the Wage Act, but because Mechanical proffered as a defense that Clemons demanded that he be paid differently from all other employees. We conclude that evidence regarding the Wage Act was wholly irrelevant to the issues in this case.
A. Relevance of the Wage Act to Clemons’
Claim of Retaliatory Discharge
Clemons’ initial complaint alleged that "in retaliation for filing the worker’s compensation claim, [Mechanical] wrongfully discharged [Clemons].” Clemons’ amended complaint (filed after the close of all evidence) alleged, in relevant part:
"10. *** [Mechanical] intentionally interfered with and restrained [Clemons’] rights under the Workers’ Compensation Act in violation of 820 ILCS 305/4(h) [(West 1994)].
13. *** [I]n retaliation of [Clemons’] exercise of his statutory rights, [Mechanical] wrongfully discharged [Clemons].”
During trial court arguments on Clemons’ motion for leave to file an amended complaint, he stated as follows:
"That [(the Wage Act)] is not what we are alleging in this case; that is what [Mechanical] is alleging as [its] reason for terminating [Clemons]. Our complaint alleges that [Clemons] was terminated in retaliation for his filing of a workers’ compensation claim. The [Wage Act] came up *** as Mechanical Devices’ defense in this case.”
Prior to granting Clemons leave to file an amended complaint, the court specifically noted that the "statutory rights” referred to in paragraph 13 of the amended complaint "are in fact the workmen’s compensation] statutory rights.”
Thus, the only allegation of retaliatory discharge properly before the jury involved Clemons’ filing a workers’ compensation claim. To prove a retaliatory discharge for filing a workers’ compensation claim, a plaintiff must show that (1) he was an employee before the injury; (2) he exercised a right granted by the Workers’ Compensation Act (820 ILCS 305/1 et seq. (West 1994)); and (3) he was discharged and the discharge was causally related to his filing a claim under the Workers’ Compensation Act. Gonzalez v. Prestress Engineering Corp., 194 Ill. App. 3d 819, 823, 551 N.E.2d 793, 796 (1990). Accordingly, Clemons did not have to show that Mechanical had violated the Wage Act in order to prove a retaliatory discharge for filing a workers’ compensation claim.
B. Relevance of the Wage Act to Mechanical’s Defense Although Clemons agrees that he did not allege that Mechanical *249wrongfully discharged him in violation of the Wage Act, he nonetheless contends that evidence regarding that act and whether Mechanical violated it was relevant because Mechanical proffered as a defense that Clemons ended his employment with Mechanical as a result of his demand that he be paid differently from other employees. We disagree.
As Clemons correctly points out, in Miller v. J.M. Jones Co., 225 Ill. App. 3d 799, 803, 587 N.E.2d 654, 658 (1992), this court discussed the three-tier allocation of proof in Civil Rights Act cases (42 U.S.C. § 2000e et seq. (1994)), as described by the Supreme Court in McDonnell Douglas Corp. v. Green, 411 U.S. 792, 36 L. Ed. 2d 668, 93 S. Ct. 1817 (1973), although in Miller we called it the "standard of proof.” In Miller, we noted that some courts utilize that standard in retaliatory discharge cases. Under the three-tier allocation of proof, the plaintiff makes out a minimal prima facie case of retaliatory discharge. Once the plaintiff does this, the burden shifts to the defendant to rebut the prima facie case by presenting some legitimate, nonretaliatory reason for the plaintiff’s discharge. If the defendant meets his burden, the presumption raised by the prima facie case is rebutted, and the plaintiff must satisfy the ultimate burden of proof by showing that the defendant’s reason for the discharge is pretextual. See Miller, 225 Ill. App. 3d at 803, 587 N.E.2d at 658.
In Miller, however, this court neither applied nor adopted the three-tier allocation of proof in retaliatory discharge cases. To the extent that other courts have adopted that allocation of proof in such cases (see Hugo v. Tomaszewski, 155 Ill. App. 3d 906, 508 N.E.2d 1139 (1987); Bragado v. Cherry Electrical Products Corp., 191 Ill. App. 3d 136, 547 N.E.2d 643 (1989)), we decline to follow them. In the context of a retaliatory discharge claim, it would simply make no sense to require the defendant to put forth a legitimate, nonretaliatory reason for its discharge of the plaintiff. As our supreme court wrote in Hartlein v. Illinois Power Co., 151 Ill. 2d 142, 159, 601 N.E.2d 720, 728 (1992):
"Despite the revolutionizing effect of Kelsay [v. Motorola, Inc., 74 Ill. 2d 172, 384 N.E.2d 353 (1978)], the common law doctrine that an employer may discharge an employee-at-will for any reason or for no reason remains the law in Illinois. [Citation.] Kelsay only excepts discharges which violate a clearly mandated public policy.” (Emphasis added.)
In Kelsay, the supreme court first recognized the tort of retaliatory discharge as an exception to the general rule that "at-will” employment is terminable at any time for any reason or no reason.
In addition, as this court wrote in Foiles v. North Greene Unit *250 District No. 3, 261 Ill. App. 3d 186, 188-89, 633 N.E.2d 24, 26 (1994), quoting 30 C.J.S. Employer-Employee Relationship § 35, at 67, § 40, at 70-71 (1992):
" '[A]t common law the right of the employer to terminate the employment is unconditional and absolute.’
* * *
'*** [A]n employment for an indefinite term may be terminated at the will of either party, regardless of the length of service, for or without cause, and without giving any reason or explanation therefor ***.’ ” (Emphasis added.)
Because the common law doctrine of employment at will continues to be the law of this state, we hold that the three-tier allocation of proof that applies in the Civil Rights Act cases does not apply in the context of retaliatory discharge claims. Thus, the defendant in a retaliatory discharge action is not required to put forth evidence of a legitimate, nonretaliatory reason (or, for that matter, any reason) for its discharge of the plaintiff. To hold otherwise would essentially abrogate the common law doctrine of employment at will.
However, the defendant may choose to provide a reason for its discharge of the plaintiff. The supreme court has held that "[t]he element of causation is not met if the employer has a valid basis, which is not pretextual, for discharging the employee.” Hartlein, 151 Ill. 2d at 160, 601 N.E.2d at 728. In this regard, we reject Clemons’ contention that the causation element is satisfied merely because the defendant states that it fired the plaintiff for an invalid (illegal) reason unrelated to the retaliatory discharge claim. Considering that (1) a retaliatory discharge claim is a narrowly circumscribed exception to the common law doctrine of employment at will, and (2) the ultimate issue concerning the causation element is the employer’s motive for discharging the employee (see Hartlein, 151 Ill. 2d at 163, 601 N.E.2d at 730), we hold that a "valid basis” means valid in the context of plaintiff’s claim of retaliatory discharge for plaintiff’s having filed a claim under the Workers’ Compensation Act.
Such a valid basis may indeed be "invalid” in other contexts. For example, a defendant may proffer as a reason for its discharge of a plaintiff-employee that the employee was discharged because of (1) his age (see Mein v. Masonite Corp., 124 Ill. App. 3d 617, 618, 464 N.E.2d 1137, 1139 (1984) (where the court held that plaintiff could not state an independent cause of action for wrongful discharge on the basis of age because of the comprehensive remedies provided in the Illinois Human Rights Act (775 ILCS 5/1 — 101 et seq. (West 1994)))); (2) the employee’s gender (actionable pursuant to the Civil Rights Act of 1964 as amended by the Equal Employment Op*251portunity Act of 1972 (42 U.S.C. § 2000e (1994))); or (3) the employee’s disability (actionable pursuant to the Illinois Human Rights Act (see 775 ILCS 5/1 — 101 et seq. (West 1994))). Thus, the defendant in a retaliatory discharge action — if it so chooses — may provide any reason for its discharge of the plaintiff, so long as the reason is not part of the plaintiff’s claim of retaliatory discharge for his having filed a workers’ compensation claim.
Applying these principles to the present case, Mechanical was not required to provide any reason for its discharge of Clemons. However, it chose to proffer a reason, namely, that Clemons demanded to be paid differently from all other Mechanical employees and contrary to the manner in which employees always had been paid for weeks partially worked that abutted vacation weeks. That reason was "valid” in the context of a retaliatory discharge claim. Whether Mechanical was violating the Wage Act (see 820 ILCS 115/1 et seq. (West 1994)) is wholly irrelevant to the trier of fact’s ultimate causation determination, namely, whether Mechanical wrongfully discharged Clemons for filing a workers’ compensation claim.
In this case, the trial court repeatedly allowed in testimony regarding the Wage Act, including erroneously allowing Fillingham to read and interpret portions of the Wage Act to mean that Mechanical’s method of payment violated the Wage Act. See Town of the City of Bloomington v. Bloomington Township, 233 Ill. App. 3d 724, 735, 599 N.E.2d 62, 69 (1992) ("A court should not permit opinion on a question of law [citations] unless the court is dealing with a question of foreign law”); see also Magee v. Huppin-Fleck, 279 Ill. App. 3d 81, 86, 664 N.E.2d 246, 249 (1996) (expert testimony concerning statutory interpretation is not proper, even if the witness is an attorney). Because the Wage Act is irrelevant to the issues in the present case, we hold that the court clearly abused its discretion by allowing in any testimony regarding that act. See Gill v. Foster, 157 Ill. 2d 304, 312-13, 626 N.E.2d 190, 194 (1993) (a reviewing court will not reverse a trial court’s admission of evidence on relevance grounds absent a clear abuse of discretion).
C. Prejudice to Mechanical
Mechanical further contends that the admission of the evidence regarding the Wage Act — particularly when viewed together with the trial court’s instructing the jury on that act and Clemons’ statements during closing argument — "served only to confuse the jury and severely prejudiced [Mechanical].” We agree.
The trial court instructed the jury (at Clemons’ request) essentially as follows. The Wage Act provides that all wages earned by *252an employee during a weekly pay period shall be paid no later than seven days after the end of the weekly pay period in which the employee earned the wages. Further, any employer who knowingly discharges or discriminates against an employee because that employee (1) has complained to the employer, the State Director of Labor, or his authorized representative, that the employer has not paid him in accordance with the Wage Act, or (2) has instituted a proceeding under or related to the Wage Act, or (3) has testified or is about to testify in an investigation or proceeding under the Wage Act, is guilty, upon conviction, of a Class C misdemeanor.
This instruction was a modified version of Illinois Pattern Jury Instructions, Civil, No. 60.01 (3d ed. 1995) (hereinafter IPI Civil 3d) and, as such, should not be given unless some evidence existed to support a finding that the defendant’s violation of the statute was the proximate cause of the plaintiff’s injury. French v. City of Springfield, 65 Ill. 2d 74, 81, 357 N.E.2d 438, 441-42 (1976); see also IPI Civil 3d No. 60.01, Notes on Use (which provides that "[t]his instruction should be given only where the evidence would support a finding that the injury complained of was proximately caused by a violation of a statute”).
Because the Wage Act is irrelevant to the issues in this case, this instruction may have confused the jury as to the issues before it and prejudiced Mechanical in its defense — which was that Clemons left because of a dispute over how Mechanical paid his wages. Thus, it was critical to Mechanical’s defense that the jury understood that the only determination it needed to make regarding Mechanical’s payment method was whether Clemons’ demand to be paid differently than other employees constituted Mechanical’s motive for discharging him.
In addition, the effect of this erroneous instruction was heightened during closing argument, when Clemons stated as follows:
"[Clemons’ attorney]: If Mechanical Devices starts discharging their at-will employees because of the color of their skin, they are liable. If they start discharging their employees for their gender, they are liable. If they start discharging their employees in violation of Illinois statute, they are liable. It is as simple as that. Read the statute.” (Emphasis added.)
This comment — which the jury could easily have understood to be a reference to the Wage Act (the "statute” that the court quoted to the jury at Clemons’ request) — may well have confused the jury regarding the issues before it and whether a violation of the Wage Act could support a finding of retaliatory discharge.
Under the circumstances of this case, we conclude that the trial *253court’s error in admitting evidence regarding the Wage Act and instructing the jury on that statute — when viewed together with Clemons’ comments during closing argument — seriously prejudiced Mechanical in its defense so as to deprive Mechanical of a fair trial. Accordingly, we reverse the judgment for Clemons and remand for a new trial.
III. ISSUES ON REMAND
Although we have determined this case must be remanded for a new trial, Mechanical raises other issues that will likely arise on remand. We address these issues separately.
A. The Trial Court’s Refusal To Allow Mechanical To Cross-Examine Clemons as to His Testimony at the DES Hearing
Mechanical argues that the trial court erred by refusing to allow it to cross-examine Clemons regarding what he testified to at a hearing in 1989 before the Department of Employment Security (DES) on Clemons’ claim for unemployment compensation. We disagree.
Where the language expressed in a statute is clear and unambiguous, a court’s proper function is to enforce the law as enacted by the legislature. Hinojosa v. Joslyn Corp., 262 Ill. App. 3d 673, 677, 635 N.E.2d 546, 549 (1994). A court construing a statute should read it as a whole, give the statutory language its plain meaning, and import to the statute the fullest possible meaning to which it is susceptible. Central Illinois Public Service Co. v. Illinois Commerce Comm’n, 268 Ill. App. 3d 471, 484, 644 N.E.2d 817, 826 (1994). Further, in Howard v. Forbes, 185 Ill. App. 3d 148, 152, 541 N.E.2d 685, 688 (1989), this court held that "the court must enforce the statutory privilege [of section 1900 of the Unemployment Insurance Act (Insurance Act) (Ill. Rev. Stat. 1987, ch. 48, par. 640)] as enacted without resorting to other interpretation tenets.”
Section 1900(A) of the Insurance Act now provides as follows:
"Except as provided in this Section, information obtained from any individual or employing unit during the administration of this Act shall:
1. be confidential,
2. not be published or open to public inspection,
3. not be used in any court in any pending action or proceeding,
4. not be admissible in evidence in any action or proceeding other than one arising out of this Act.” (Emphasis added.) 820 ILCS 405/1900(A) (West 1994).
We note that this section included the same language in its 1989 ver*254sion, which was in effect at the time of the DES hearing. See Ill. Rev. Stat. 1989, ch. 48, par. 640.
Giving this statutory language its plain and fullest possible meaning, we conclude that "information obtained from any individual” means just that and thereby prevents disclosure of information obtained from the claimant in any action or proceeding arising outside of the Insurance Act. To the extent McMahon v. Richard Gorazd, Inc., 135 Ill. App. 3d 211, 224, 481 N.E.2d 787, 796 (1985), holds otherwise, we decline to follow it. Thus, we conclude that cross-examination of Clemons regarding what he testified to at the 1989 DES hearing is prohibited by section 1900(A) of the Insurance Act. Accordingly, we hold that the trial court did not err by refusing to allow Mechanical to cross-examine Clemons as to his testimony at the 1989 DES hearing.
B. The Trial Court’s Refusal To Allow a Witness To Testify Regarding Payments Made by Clemons’ Health Insurance Company
The material in this section is not to be published pursuant to Supreme Court Rule 23. 166 111. 2d R. 23.
C. The Trial Court’s Refusal To Give Mechanical’s Nonpattern Instruction Defining "At Will” Employment to the Jury
The material in this section is not to be published pursuant to Supreme Court Rule 23.
D. Punitive Damages
The material in this section is not to be published pursuant to Supreme Court Rule 23.
IV. CONCLUSION
For the reasons stated, we reverse and remand for a new trial consistent with the views expressed herein.
Reversed and remanded.
McCullough, j., concurs.