delivered the opinion of the court:
After surgery left Richard McCorry paralyzed, he and his wife, Barbara McCorry, sued the surgeon, Dr. Thomas Hurley, the radiologist, Dr. Nihal Gooneratne, and Christ Hospital, where Hurley performed the surgery. The trial court granted Gooneratne’s motion *938for summary judgment because it found no evidence that Gooneratne’s alleged negligence had any causal connection to the injuries. Plaintiffs appeal from that judgment in docket number 1 — 00 — 1954. Christ Hospital moved to dismiss one count of the amended complaint based on the statute of limitations. The trial court granted the motion, holding that the count did not relate back to the original complaint. Plaintiffs appeal from that ruling in docket number 1 — 00— 3352. We consolidated the appeals.
BACKGROUND
Richard had back pain that prevented him from sitting for prolonged periods. The pain steadily worsened through 1993 and early 1994, to the point that Richard could no longer drive. In June 1994 Dr. Andrew Kazaniwskyj admitted Richard to Christ Hospital for a neurosurgery consultation. Hurley, a neurosurgeon, examined Richard and ordered a magnetic resonance imaging (MRI) test of the upper part of Richard’s spine, the part in his neck. Gooneratne reported that the MRI showed disc herniation at two locations.
Hurley performed the surgery on October 27, 1994. When Richard awoke after surgery, Hurley tested his condition and found Richard unable to move his legs. Hurley ordered a new MRI. Although he discussed the possibility of further surgery with plaintiffs, he did not recommend surgery, as he had little hope of restoring any function to the legs. Richard remains paralyzed.
Plaintiffs filed their original complaint on October 25, 1996, alleging as follows:
“On or about June 15, 1994, NIHAL GOONERATNE, M.D., administered and interpreted diagnostic MRI films of RICHARD MCCORRY’s cervical spine at CHRIST HOSPITAL[.]
^ ^
*** HURLEY *** [m]isread and misinterpreted the MRI films of the Plaintiff’s cervical spine; [and a]pplied additional and unnecessary pressure to the Plaintiff’s spinal cord during surgery ***.
*** GOONERATNE *** [m]isread and misinterpreted the MRI films of the Plaintiffs cervical spine.”
Plaintiffs claimed that Richard’s paralysis resulted from the negligence. Plaintiffs sought to hold Christ Hospital liable based on respondeat superior; they alleged no negligence of Christ Hospital apart from the negligence of the named doctors.
No. 1 — 00 — 1954
In his deposition Hurley swore that he interpreted the MRI films *939himself when he performed the operation. He did not rely on Gooneratne’s report. Gooneratne moved for summary judgment, and he attached to his motion an excerpt from the transcript of the deposition. Plaintiffs missed the initial date for a response to the motion and sought an extension of time. The trial court allowed extra time but added that plaintiffs should respond with “Counter-Affidavits only.” After plaintiffs filed their affidavits but no brief, the court denied the motion for summary judgment because Gooneratne failed to supply all relevant portions of Hurley’s deposition.
Gooneratne moved for reconsideration, supporting the motion with the complete transcript of Hurley’s deposition. By order dated January 28, 2000, the court set the motion for ruling on February 28, 2000. Plaintiffs did not seek leave to respond to the motion, for reconsideration. On February 28, 2000, the court granted the motion for reconsideration and entered summary judgment in favor of Gooneratne. The court added, “This finding is made pursuant to Supreme Court Rule 3204(a) [sic] thus there is no just reason to delay the enforcement or appeal of this order.”
Plaintiffs moved to reconsider the judgment and fully briefed the merits of the summary judgment motion. By order dated April 19, 2000, the trial court denied the motion for reconsideration, stating that the “summary judgment entered in favor of Dr. Nihal Gooneratne on February 28, 2000 stands.” On May 16, 2000, plaintiffs moved for a finding that the order denying the motion to reconsider was final and appealable. The court granted the motion by order dated May 22, 2000. Plaintiffs filed their notice of appeal for docket number 1 — 00— 1954 on June 2, 2000.
Gooneratne asks this court to dismiss plaintiffs’ appeal for want of jurisdiction. Supreme court rules narrowly circumscribe this court’s jurisdiction. If the appellant fails to comply with the deadline for appeals provided in Supreme Court Rule 303 (155 Ill. 2d R. 303), this court lacks authority to consider the appeal. See Bernhauser v. Glen Ellyn Dodge, Inc., 288 Ill. App. 3d 984, 989, 683 N.E.2d 1194 (1997). When the trial court finds no reason to delay enforcement or appeal of a judgment that is final with respect to one of multiple parties to a case, the appellant must file the notice of appeal within 30 days after disposition of postjudgment motions. 155 Ill. 2d Rs. 303(a)(1), 304(a).
Here the trial court purported to enter a final judgment in favor of Gooneratne on February 28, 2000. The court expressly found no reason to delay enforcement or appeal, apparently rendering the judgment immediately appealable under Supreme Court Rule 304. 155 Ill. 2d R. 304(a); Reyes v. Compass Health Care Plans, 252 Ill. App. 3d *9401072, 1078, 625 N.E.2d 246 (1993). Plaintiffs filed a timely postjudgment motion for reconsideration, tolling the time for appeal. Elmhurst Auto Parts, Inc. v. Fencl-Tufo Chevrolet, Inc., 235 Ill. App. 3d 88, 90, 600 N.E.2d 1229 (1992). Plaintiffs had 30 days from the denial of their motion for reconsideration in which to file the notice of appeal. They did not do so. Instead, they later filed a motion for a second finding of appealability and filed a notice of appeal after the court granted that motion. Even if we construed the motion for a finding of appealability as a postjudgment motion, the appeal filed after that finding would not be timely, because a second successive postjudgment motion does not toll the time for appeal. Sears v. Sears, 85 Ill. 2d 253, 259, 422 N.E.2d 610 (1981).
Plaintiffs try several different theories to show that the rules authorize this court to hear this appeal. First plaintiffs suggest that the order dated February 28, 2000, lacked the finding requisite for appealability under Rule 304(a). Although the court found no just reason to delay appeal, the court made the finding pursuant to a nonexistent “Rule 3204(a).” In re Application of Du Page County Collector, 152 Ill. 2d 545, 605 N.E.2d 567 (1992), established applicable standards for Rule 304(a) findings. When the judgment dismisses a count of the complaint, the court must refer to the judgment’s immediate appeal-ability. Du Page County, 152 Ill. 2d at 550-51. Other language found here is unnecessary surplusage with no effect on appealability. Du Page County, 152 Ill. 2d at 549-50. The court here made the finding requisite for immediate appealability.
Plaintiffs argue that the order dated Februaiy 28, 2000, was not a final judgment. Plaintiffs point out that the trial court here failed to hold a hearing on the summary judgment motion before entering the order of February 28, 2000, and court rules require such a hearing.
A judgment is final if it determines the rights of the parties on some definite part of the litigation. Citicorp Savings of Illinois v. First Chicago Trust Co. of Illinois, 269 Ill. App. 3d 293, 296-97, 645 N.E.2d 1038 (1995). The order of February 28, 2000, granted Gooneratne summary judgment on the only claim against him, thereby terminating the litigation against him. That order constitutes a final judgment unless it is void, and it is void only if the court lacked jurisdiction to enter the judgment (People v. Davis, 156 Ill. 2d 149, 155, 619 N.E.2d 750 (1993)), or if a party procured the judgment through fraud (Terra-Nova Investments v. Rosewell, 235 Ill. App. 3d 330, 335, 601 N.E.2d 1109 (1992)).
Plaintiffs have not argued that fraud contributed to the judgment. Our supreme court in Steinbrecher v. Steinbrecher, 197 Ill. 2d 514, 531, 759 N.E.2d 509 (2001), held that a judgment is not void for want *941of jurisdiction as long as the court has both subject matter jurisdiction and personal jurisdiction over the parties. Plaintiffs, who sought the circuit court’s adjudication of their claims, do not dispute its subject matter jurisdiction or its personal jurisdiction over them. Accordingly, the judgment in favor of Gooneratne entered on February 28, 2000, was a valid final judgment disposing of the claim against him. Any error or irregularity in its entry cannot affect its validity as a final judgment. See Miller v. Balfour, 303 Ill. App. 3d 209, 216, 707 N.E.2d 759 (1999).
Next, plaintiffs claim that they could not appeal until the court added Rule 304(a) language to the order denying their motion for reconsideration. Rule 303(a)(1) provides that parties have 30 days from disposition of the posttrial motion in which to appeal. 155 Ill. 2d R. 303(a)(1). The rules do not require a second finding of appealability in the order denying any posttrial motion. Waters v. Reingold, 278 Ill. App. 3d 647, 652 n.5, 663 N.E.2d 126 (1996), overruled on other grounds, Niccum v. Botti, Marinaccio, DeSalvo & Tameling, Ltd., 182 Ill. 2d 6, 8-9, 694 N.E.2d 562 (1998). The order denying a motion for reconsideration is not itself appealable, and it is not a judgment. Sears, 85 Ill. 2d at 258. As Rule 304(a) requires the finding of appealability only for final judgments, the judgment against one of several parties becomes appealable with the disposition of the postjudgment motion without any separate finding of appealability for the order concerning the postjudgment motion. Therefore the lack of Rule 304(a) language in the order denying the motion for reconsideration had no effect on the time for appeal.
The time for appeal began when the court denied the postjudgment motion by order dated April 19, 2000. The trial court lost jurisdiction 30 days later, on May 19, 2000. In re Marriage of Breslow, 306 Ill. App. 3d 41, 49, 713 N.E.2d 642 (1999). But plaintiffs moved for addition of Rule 304(a) language to the order denying the postjudgment motion. The court entered an order dated May 22, 2000, granting the request for appealability language. Plaintiffs now contend that Gooneratne’s counsel appeared in court and argued the merits in response to the motion for additional language, without challenging the court’s jurisdiction, thereby revesting the court with jurisdiction.
The record includes no transcript of the hearing on the motion, and the court’s order makes no reference to the arguments of the parties. Thus, the record does not support plaintiffs’ claim that Gooneratne’s counsel argued the merits, failed to contest the court’s jurisdiction, or even appeared at the hearing. We cannot presume that we have authority to decide an appeal on the basis of a record insufficient to show our jurisdiction. See Nenadic v. Grant Hospital, 75 Ill. App. 3d 614, 625, 394 N.E.2d 527 (1979).
*942Moreover, even if Gooneratne appeared and argued against the motion for a finding of appealability, the conduct would not revest the trial court with jurisdiction. In Sears, 85 Ill. 2d at 256, the trial court entered judgment for Conde Sears and Gerald Sears moved to reopen the judgment on grounds that he did not have notice of a prior hearing that led to the judgment. The court denied the motion. Nearly 30 days later Gerald moved again to reopen the judgment, adding facts not mentioned in the prior motion. Months later the court held a hearing in which the parties presented evidence concerning notice of the prior hearing. The court again denied the motion to reopen the judgment and Gerald appealed. He argued that Conde revested the court with jurisdiction by presenting evidence in the hearing held months after the court lost jurisdiction. Our supreme court rejected the argument, noting that the parties did not retry the case. Nothing in Conde’s actions treated the judgment in her favor as anything less than a valid, binding judgment. Sears, 85 Ill. 2d at 260.
Similarly, nothing in Gooneratne’s actions treated the judgment in his favor as anything less than a valid judgment, as he, like Conde, sought to uphold the validity of the judgment. His participation without raising a jurisdictional objection here, like Conde’s in Sears, did not revest the trial court with jurisdiction. Because plaintiffs failed to file a notice of appeal between April 19, 2000, and May 19, 2000, we lack jurisdiction to consider the appeal in docket number 1 — 00— 1954.
No. 1 — 00 — 3352
In November 1999 the trial court permitted plaintiffs to file an amended complaint, adding a count addressed specifically to Christ Hospital. Plaintiffs alleged that the hospital:
“a. failed to have in effect a policy requiring prompt transmittal of radiologists’ findings to surgeons in cases of emergent postoperative MRI evaluations;
b. failed to have in effect a sufficient or a written policy requiring prompt transmittal of radiologists’ findings to surgeons in cases of emergent post-operative MRI evaluations;
c. failed to timely perform and interpret RICHARD McCORRY’s post-operative MRI on 10-27-94;
d. failed to accurately interpret RICHARD McCORRY’s postoperative MRI on 10-27-94.”
Christ Hospital moved to dismiss the count, arguing that the statute of limitations barred the new claims. The trial court agreed with Christ Hospital and dismissed the count. At plaintiffs’ request, the court later added a finding of no just cause to delay enforcement or appeal of the dismissal. Plaintiffs filed a timely notice of appeal, so *943Rule 304(a) gives us jurisdiction to decide the appeal in docket number 1 — 00 — 3352.
We review de novo the decision to dismiss the count. Shaker & Associates, Inc. v. Medical Technologies Group, Ltd., 315 Ill. App. 3d 126, 131, 733 N.E.2d 865 (2000). Oddly, we would review for abuse of discretion if the trial court had denied plaintiffs leave to amend based on the statute of limitations (see Cochran v. Perry County Road District No. 1, 295 Ill. App. 3d 1089, 1094, 695 N.E.2d 65 (1998)), but because the court here permitted the amendment and then dismissed the count based on the statute of limitations, we review the judgment de novo.
The applicable statute of limitations requires filing of the complaint within two years of the date on which the plaintiffs knew or should have known of the injury for which they seek compensation. 735 ILCS 5/13 — 212(a) (West 1994). The limitations period begins to run when a plaintiff has sufficient information to put a reasonable person on inquiry to determine whether actionable conduct caused the injury, even if the plaintiff lacks knowledge of a specific person’s negligent conduct. Walters v. Marion Memorial Hospital, 217 Ill. App. 3d 744, 746, 577 N.E.2d 915 (1991). Thus, the limitations period does not begin anew each time pretrial discovery reveals that unsued persons may be liable or that other theories of liability may apply.
The surgery on October 27, 1994, left Richard paralyzed. Plaintiffs do not allege or argue that they discovered that actionable conduct may have caused the injury at any later date before the filing of the lawsuit. Accordingly, the limitations period for their claims in this lawsuit expired on October 27, 1996, two days after they filed their original complaint. The claim in the amended complaint, filed in December 1999, came too late unless the count relates back to the original complaint.
According to section 2 — 616(b) of the Code of Civil Procedure:
“The cause of action *** set up in any amended pleading shall not be barred by lapse of time under any statute *** limiting the time within which an action may be brought ***, if the time prescribed or limited had not expired when the original pleading was filed, and if it shall appear from the original and amended pleadings that the cause of action asserted *** grew out of the same transaction or occurrence set up in the original pleading, *** and for the purpose of preserving the cause of action, *** an amendment to any pleading shall be held to relate back to the date of the filing of the original pleading so amended.” 735 ILCS 5/2 — 616(b) (West 1998).
The later claim “grew out of the same *** occurrence” as the claim in the original complaint if the original complaint provided the *944defendant with all of the information necessary for preparation of the defense for the claim asserted later. Williams v. Board of Education of the City of Chicago, 222 Ill. App. 3d 559, 563, 584 N.E.2d 257 (1991). The later claim relates back if the original complaint directs the defendant’s attention to the facts on which the plaintiff bases the later claim. Williams, 222 Ill. App. 3d at 563.
Here, nothing in the original complaint indicated any problem in the transmittal of radiologists’ findings to surgeons. A defense to the original claim in no way prepared Christ Hospital to defend its policies regarding transmittal of radiology reports. In subparagraphs a and b quoted above from the amended complaint, plaintiffs alleged that Christ Hospital negligently failed to have a sufficient written policy requiring prompt postoperative transmittal of such reports to surgeons. These allegations involve conduct by different persons at times different from the occasions of the negligent acts alleged in the original complaint. Because the original complaint did not direct Christ Hospital’s attention to the allegedly negligent conduct of its officers responsible for instituting and enforcing policies for transmittal of radiological reports to surgeons, the allegations of subparagraphs a and b in the amended complaint do not relate back to the original complaint. See Weidner v. Carle Foundation Hospital, 159 Ill. App. 3d 710, 713, 512 N.E.2d 824 (1987); Kennedy v. King, 252 Ill. App. 3d 52, 56, 623 N.E.2d 955 (1993).
In subparagraphs c and d of the count added to the amended complaint, plaintiffs allege that Christ Hospital’s employees failed to interpret the postoperative MRIs accurately and promptly. The original complaint included the charge that agents of Christ Hospital misinterpreted MRIs. But the original complaint makes no reference to postoperative MRIs, and does not even assert that Richard had an MRI after the operation. While several paragraphs in the original complaint refer to “the MRI films” without further specification, all such references appear after the factual assertion that “[o]n or about June 15, 1994, NIHAL GOONERATNE, M.D., administered and interpreted diagnostic MRI films of RICHARD MCCORRY’s cervical spine.” Thus the original complaint drew the hospital’s attention to the June 15 MRI and alerted the hospital to the need to defend the interpretation of that set of MRI films.
Preparation of a defense to the original complaint would not have included a defense of the interpretation of postoperative MRI films. The defense can defeat a claim based on the postoperative MRI by proving that the alleged misinterpretation and delayed transmittal had no effect on plaintiffs’ injuries. If Richard suffered irreversible paralysis in the surgery, any misinterpretation or delay in transmittal *945of the postoperative MRIs had no effect on his condition. But if a second surgery shortly after the initial surgery stood a good chance of correcting the paralysis, the misinterpretation or delay in the transmittal of the postoperative MRIs might have a causal connection to Richard’s current condition. Nothing in the original complaint suggested that a second surgery might have corrected Richard’s paralysis, and nothing in the original complaint alerted the hospital to the need to search for evidence concerning the potential reversibility of the paralysis. Because the preparation of a defense to the allegations of delay and misinterpretation of postoperative MRIs would involve an investigation into facts completely irrelevant to the defense against the original complaint, the new allegations do not relate back to the original complaint. See Cammon v. West Suburban Hospital Medical Center, 301 Ill. App. 3d 939, 947, 704 N.E.2d 731 (1998).
Plaintiffs claim that McArthur v. St. Mary’s Hospital of Decatur, 307 Ill. App. 3d 329, 717 N.E.2d 501 (1999), and Figueroa v. Illinois Masonic Medical Center, 288 Ill. App. 3d 921, 681 N.E.2d 64 (1997), require a different result. We disagree. In McArthur the original complaint included allegations that several defendants misinterpreted specified sonograms and X rays, but the count against the hospital charged only a failure to preserve sonograms. The amended complaint charged the hospital with misinterpreting the same sonograms and X rays identified in the original complaint. The original complaint adequately directed attention to facts concerning the sonograms and X rays and alerted the hospital to the potential need to defend the interpretation of those sonograms and X rays. The court explicitly distinguished cases of amended complaints including charges that the plaintiffs had not directed against any defendants in the original complaint. See McArthur, 307 Ill. App. 3d at 335. The original complaint here did not charge any defendant with misinterpretation of postoperative MRI films, as the complaint did not mention such films.
In Figueroa the original complaint alleged that the defendant treated the plaintiff’s pregnancy negligently, especially after the delivery. The court found the complaint broad enough to alert the defense to the need to explain all of its treatment of the plaintiff through the birthing process, both before and after delivery. An investigation into the plaintiffs postdelivery condition would involve an investigation into the causes of that condition, including her predelivery condition and the treatment she received during the birthing process.
As the trial court here observed, the Figueroa decision appears to reward vagueness in the original complaint. Here, however, plaintiffs *946specifically identified the June 15 MRI films as the subjects of defendants’ negligent misinterpretation. The complaint alerted the defense to the need to defend the interpretation of only the films specifically identified, and the complaint did not even mention any other films. The complaint entitled defendants to presume that plaintiffs intended to refer back to the films already specified, when plaintiffs in later paragraphs alleged negligent misinterpretation of “the MRI films.” Figueroa and McArthur do not require reversal of the judgment here.
Plaintiffs also argue that Christ Hospital had notice of the significance of the postoperative MRI films because its doctors ordered the MRI immediately following the surgery, once they realized Richard was paralyzed. Christ Hospital’s doctors examined the MRI to determine what had gone wrong in Richard’s surgery. Thus, two years before plaintiffs filed the lawsuit, Christ Hospital knew that the postoperative MRIs provided significant evidence concerning Richard’s injury.
An amended complaint that differs materially from the original complaint may relate back, as long as the defendant had clear notice of the facts included in the amendment prior to the expiration of the limitations period. Williams, 222 Ill. App. 3d at 563. Thus, where discovery completed during the limitations period alerts the defendant to facts supporting a new claim, a later amendment including the new claim may relate back to the original filing. Wolf v. Meister-Neiberg, Inc., 143 Ill. 2d 44, 48, 570 N.E.2d 327 (1991). The rationale for permitting relation back “is that a defendant will not be prejudiced by an amendment so long as ‘his attention was directed, within the time prescribed or limited, to the facts that form the basis of the claim asserted against him.’ ” Boatmen’s National Bank v. Direct Lines, Inc., 167 Ill. 2d 88, 102, 656 N.E.2d 1101 (1995), quoting Simmons v. Hendricks, 32 Ill. 2d 489, 495, 207 N.E.2d 440 (1965). That is, the defendant must have notice not only of the operative facts, but also of the plaintiff’s intention to assert a claim on the basis of those facts. A defendant’s investigation outside the context of litigation does not help an amendment relate back to the original complaint, because the investigation cannot inform the defendant of the intention of the plaintiff or anyone else to assert liability on the basis of the facts found in the investigation.
Here, the hospital’s records of a postoperative MRI do not inform the hospital that plaintiffs intend to claim that the hospital misinterpreted the MRIs. Thus, the defendants’ postoperative investigation into the cause of Richard’s paralysis does not make the belated amendment relate back to the original complaint.
*947Finally, plaintiffs argue that the court should estop the hospital from raising the statute of limitations as a defense because the hospital failed to respond promptly to all discovery requests, including requests for depositions. “Equitable estoppel arises through a party’s voluntary conduct whereby he is precluded from asserting his rights against another who in good faith relied on such conduct and was thereby led to change his position to his detriment.” Ciers v. O.L. Schmidt Barge Lines, Inc., 285 Ill. App. 3d 1046, 1049, 675 N.E.2d 210 (1996). When a plaintiff seeks estoppel of a defendant who asserts that a limitations period bars the claim, the plaintiff generally cannot rely on acts occurring after the period has ended. Ciers, 285 Ill. App. 3d at 1049. The plaintiff cannot have relied on such acts when he delayed presenting his claim.
Here the statutory period ended two days after plaintiffs filed their complaint, and before plaintiffs began the discovery process. Plaintiffs cannot have relied on the conduct of any discovery in delaying amendment of the complaint until the expiration of the limitations period. The trial court had no basis for applying equitable estoppel to preclude Christ Hospital from raising the statute of limitations as a defense.
Count III of the amended complaint, concerning Christ Hospital’s liability for misinterpretation and delay in transmittal of postoperative MRIs, does not arise from the same occurrences as those set out in the original complaint. Because the amended count does not relate back to the original complaint, we affirm the trial court’s decision to dismiss count III of the amended complaint.
We lack jurisdiction to consider plaintiffs’ untimely appeal from the summary judgment in favor of Dr. Gooneratne. Because the original complaint did not provide Christ Hospital with all of the facts needed for preparation of the defense to the claims asserted in the amended complaint, count III of the amended complaint does not relate back to the original complaint. The trial court correctly dismissed count III as untimely. Therefore we dismiss the appeal in docket number 1 — 00 — 1954 and we affirm the judgment in docket number 1 — 00 — 3352.
No. 1 — 00 — 1954, Appeal dismissed.
No. 1 — 00 — 3352, Affirmed.
COHEN, EJ., and COUSINS, J., concur.