The appellants, Paul A., Pauline B., and Paul G. Schmidt, bring this legal malpractice suit against attorneys C. Thomas Pearson, Jr., and Steven Tennant for their alleged negligence committed in Schmidt v. McIlroy Bank & Trust, 306 Ark. 28, 811 S.W.2d 281 (1991).1 Schmidt involved the Schmidts’ lender-liability action against Mcllroy Bank & Trust. This court affirmed an award of summary judgment dismissing the Schmidts’ suit against Mcllroy Bank because they failed to make a timely amendment to their complaint alleging their status or standing as guarantors of their corporation’s (Aero’s) debts. In other words, the Schmidts had not pled any individual cause of action under their separate guaranty contract against the Bank. Presented with a case of first impression in Schmidt, this court held that filing a motion to amend the pleadings was unnecessary under Ark. R. Civ. P. 15(a), and that until the pleadings were amended and a request was made to strike a pleading, the trial court was not required to determine whether prejudice or undue delay would result from the amendment. Because the Schmidts had had ample time to amend their *502pleadings to allege their guarantor status, but had failed to do so, we upheld the trial court’s granting of Mcllroy Bank’s second request for summary judgment, which dismissed the Schmidts’ action.
We believe a recitation of the facts leading up to the present legal malpractice action might be helpful. The Schmidts were the sole shareholders of Aero Corporation,2 a family farming and egg-producing business. The Schmidts had had a business relationship with Mcllroy Bank & Trust since 1976. At the time the lender-liability cause of action arose, Mcllroy Bank held Aero’s secured notes, mortgage, and checking accounts. The notes and the mortgage were secured by the personal guarantees of the Schmidts. In 1986, the Bank’s employees were replaced by employees of Banc-shares, which was in the process of purchasing the Bank. The evidence showed the Bank agreed to extend payments under the secured notes and to allow the Schmidts to temporarily overdraw on Aero’s checking accounts. However, after Aero overdrew its checking accounts, the Bank closed the accounts, filed a foreclosure suit in chancery court, and made demand for payment under the secured notes. The Schmidts filed for Chapter 11 bankruptcies, but voluntarily dismissed them later.
The Schmidts, through their original attorney, Larry Froelich, then filed their lender-liability complaint in circuit court against the Bank, seeking $15 million in compensatory and $1 million in punitive damages for Aero and themselves as shareholders. However, as previously noted in our discussion of Schmidt, the Schmidts failed to request relief as guarantors. While those actions in circuit and chancery court were pending, the Schmidts employed attorney, C. Thomas Pearson, Jr., to pursue their lender-liability suit and to defend the Bank’s foreclosure action. With the Schmidts’ approval, Pearson engaged the assistance of Steven Tennant as co-counsel.
In 1988, the appellants’ original counsel, Larry Froelich, withdrew, leaving Pearson and Tennant as attorneys of record in the lender-liability suit and Tennant as attorney of record in the foreclosure case. See McIlroy Bank & Trust v. Acro Corp., 30 Ark. App. 189, 785 S.W.2d 47 (1990) (where judgment for the Bank was *503reversed and remanded, because the chancellor signed the foreclosure consent decree in error). On retrial of the foreclosure action, the Bank was awarded $634,279.20 plus 10% attorney’s fee. The Schmidts’ property was sold at foreclosure for $30,000, leaving an outstanding judgment against them.
On August 3, 1990, the Schmidts filed a complaint against their attorneys for breach of contract and for legal malpractice in both the lender-liability and foreclosure actions. Specifically, the Schmidts alleged, among other things, that Pearson and Tennant willfully and negligendy allowed Aero’s corporate charter to be revoked, failed to properly dissolve Aero and preserve its cause of action against the Bank, and failed to properly amend the lender-liability complaint to include the Schmidts as guarantors. The Schmidts sought in excess of $7 million in damages and refund of all amounts paid to Pearson and Tennant. A jury trial was held on August 9-11, and September 15-16, 1994, and by interrogatories the ten-member jury found both Pearson and Tennant negligent. On September 26, the trial court entered judgment against Pearson and Tennant for damages of $880,609.74 in favor of the Schmidts and $3.1 million in favor of Aero. On that same date, Pearson and Tennant filed a motion for judgment notwithstanding the verdict, and in the alternative, for new trial and stay of judgment.
On October 25, the trial court entered its order granting Pearson and Tennant their motion for JNOV finding there was insubstantial evidence to support the verdict. The trial court also conditionally granted them a new trial because of other irregularities in the proceedings. On appeal from that order, the Schmidts argue the trial court abused its discretion in granting Pearson’s and Tennant’s motions for JNOV and new trial, and they also argue the trial court abused its discretion in finding it had erred by (1) failing to strike two veniremen; (2) failing to exclude hearsay evidence; and (3) allowing introduction of testimony regarding Pearson’s and Tennant’s expenditure of monies advanced for litigation costs. Because we find the Schmidts failed to show Pearson and Tennant negligently and proximately caused the Schmidts’ damages, we affirm.
In reviewing this matter on appeal, we are guided by the rule that a trial court may enter judgment notwithstanding the verdict only if there is no substantial evidence to support the verdict of the jury and the moving party is entitled to judgment as a matter *504of law. McLaughlin v. Cox, 324 Ark. 361, 922 S.W.2d 327 (1996). Furthermore, a trial court may not substitute its view for that of the jury, and the jury’s verdict must be clearly against the preponderance of the evidence in order to be set aside. The standard regarding a motion for a new trial is the same. See Ark. R. Civ. P. 50(b). Also, on appeal, this court views the evidence and all reasonable inferences therefrom in the light most favorable to the party for whom the original judgment was entered. McLaughlin, 324 Ark. at 368.
We next turn to those principles that control in legal malpractice actions, and we are met by the rule that an attorney is negligent if he or she fails to exercise reasonable diligence and skill on behalf of the client. Anthony v. Kaplan, 324 Ark. 52, 918 S.W.2d 174 (1996). And, in order to prevail under a claim of legal malpractice, a plaintiff must prove that the attorney’s conduct fell below the generally accepted standard of practice and that this conduct proximately cause the plaintiff damages. To show damages and proximate cause, the plaintiff must show that but for the alleged negligence of the attorney, the result in the underlying action would have been different. Id.; see also Tyson Foods, Inc. v. Adams, 326 Ark. 300, 930 S.W.2d 374 (1996); Callahan v. Clark, 321 Ark. 376, 901 S.W.2d 842 (1995); Shaffer v. Wilkes, 65 F.3d 115 (8th Cir. 1995); Vanderford v. Penix, 39 F.3d 209 (8th Cir. 1994).
In deciding this case, we can assume the Schmidts presented sufficient proof to have prevailed in their underlying lender-liability action against Mcllroy Bank. Even so, we conclude their evidence falls short in showing Pearson’s and Tennant’s actions negligendy and proximately caused the Schmidts’ damages. The Schmidts point to five instances where Pearson and Tennant negligently performed, causing the Schmidts to sustain damages. We consider each instance in the order the Schmidts discussed them in their brief.
The Schmidts first complain of Pearson’s and Tennant’s use of a $11,000 nonrefundable retainer for payment to themselves, other attorneys, and secretaries, rather than for discovery and copying costs. The Schmidts contend that they entered an oral, contingency contract with Pearson and Tennant, and agreed to provide them with an initial $10,000 retainer for discovery, deposition, and copying costs; apparendy, an additional $1000 was paid later. The Schmidts argue Pearson and Tennant were negligent in the use of this retainer.
*505 Whether Pearson and Tennant spent the retainer as the parties agreed is an issue dealing with breach of contract, and not one of negligence. See Robertson v. White, 633 F.Supp. 954 (W.D.Ark. 1986) (the failure to perform a promise implied in a professional relationship sounds in contract, rather than tort). On this point, we note that Paul G. Schmidt testified and conceded the $10,000 paid Pearson and Tennant was nonrefundable and, as a consequence, the evidence reflects there was no duty to return any portion of the retainer to the Schmidts. And while the Schmidts offered some testimony that the retainer should have been spent for depositions, they failed to show what depositions should have been taken or what depositions may have made a difference in proving their case. In addition, from the record as abstracted, the jury was not given an interrogatory on the Schmidts’ breach-of-contract claim, nor did the jury return a finding that a breach of the retainer contract occurred. When the issues are submitted to the jury on interrogatories, failure to request a finding on one issue is a waiver of that issue on appeal, and this court cannot say what the jury would have found. Olmstead v. Moody, 311 Ark. 163, 842 S.W.2d 26 (1992). Further, even if the retainer was negligendy used, the Schmidts fail to show that the misapplied expenditures proximately caused the loss of their lender-liability suit.
The Schmidts also complain that even though they paid this retainer on January 5, 1988, Pearson and Tennant did not enter their appearance until three months later in April. We note that the Schmidts made no argument on this issue, and this court will not consider assignments of error that are unsupported by convincing argument or authority. Fayetteville Sch. Dist. v. Ark. State Bd. of Education, 313 Ark. 1, 852 S.W.2d 122 (1993).
Second, the Schmidts contend Pearson and Tennant ignored the Bank’s settlement offer of $500,000 in the foreclosure action, and did no evaluation or investigation of their lender-liability case until after the offer was withdrawn on November 21, 1988. The Schmidts point to Tennant’s testimony that he waited so he could use the Bank’s evidence presented in the foreclosure hearing to get a “free shot” at what the Bank’s testimony would be in the lender-liability case. Tennant testified after he heard the Bank’s evidence, he “decided we had a hard, hard row to hoe.” The Schmidts contend Pearson and Tennant were negligent in not deposing the Bank’s employees while the foreclosure settlement offer was still *506viable. In response, Pearson maintains the settlement offer was discussed between the parties, and ultimately rejected.
The Schmidts presented no evidence showing the Bank’s settlement offer in the foreclosure action should have been accepted, nor if it had been accepted that its acceptance would have caused them to prevail in the lender-liability action. In fact, the Schmidts’ expert testified he had no opinion regarding whether the Bank’s settlement offer should have been accepted. Instead, the Schmidts merely assert the deficiency judgment against them would have been less had the settlement offer been accepted.
An attorney is not a guarantor that his judgment is infallible and is not liable for an error of judgment made in good faith. Spivack, Shulman & Goldman v. Foremost Liquor Store, Inc., 124 Ill. App.3d 676, 465 N.E. 500 (Ill. App. 1 Dist. 1984). Finally, from the record as abstracted, the jury was not asked to return a finding as to whether Pearson and Tennant were negligent in the foreclosure action. Without more, the Schmidts cannot claim on appeal that the attorneys’ acts in one cause of action were the proximate cause of their loss in a different cause of action.
Third, the Schmidts maintain Pearson was negligent in not dissolving Aero pursuant to Ark. Code Ann. §§ 4-26-1101 -1109 (Repl. 1991), thereby preserving Aero’s only asset of any value, namely, its lender-liability action against the Bank. For support, the Schmidts point to the statements of their legal expert, Richard Downing, who testified that a reasonable attorney would have paid Aero’s back franchise taxes and filed a certificate of dissolution, thus allowing Aero to wind down its affairs and pursue its suit against the Bank in its corporate name. Then, Downing testified, the reasonable attorney would have amended the complaint to include the Schmidts as guarantors.
But Pearson contends dissolving Aero would have resulted in the very thing the Schmidts did not want, that is the appointment of a receiver, thereby depriving the Schmidts of their assets. Pearson cites Downing’s testimony acknowledging that dissolution would have allowed Aero’s creditors to force the Schmidts into a receivership. Additionally, Pearson points out the Schmidts voluntarily withdrew from Chapter 11 bankruptcy because of the threat of receivership, and Paul G. Schmidt testified that a receivership was not an option. Finally, Pearson contends the issue of whether to *507dissolve Aero was a question of professional judgment made after discussing the issue with his clients, and after considering the consequences and whether such action would serve the best interest of his clients.
An attorney is not liable to a client when acting in good faith, he makes mere errors of judgment. Cianbro Corporation v. Jeffcoat & Martin, 804 ESupp. 784 (D.S.C. 1992); Martinson Manufacturing Co., Inc. v. Seery, 351 N.W.2d 772 (Iowa 1984); Spivack, Shulman & Goldman, 124 Ill. App.3d 676, 465 N.E.2d 500 (1 Dist. 1984); George v. Caton, 93 N.M. 370, 600 P.2d 822 (1979); Herston v. Whitesell, 348 So.2d 1054 (Ala. 1977); Talbot v. Schroeder, 13 Ariz. App. 230, 475 P.2d 520 (1970); Meagher v. Kavli, 97 N.W.2d 370 (Minn. 1959). In the present case, the evidence showed Pearson used his best judgment in not dissolving Aero, which might then be forced into receivership and liquidation. See § 4-26-1103(2) and (3).
Fourth, the Schmidts contend Pearson and Tennant should have amended the lender-liability complaint to include the Schmidts as guarantors of Aero’s debts. The Schmidts note the Bank apprised Pearson and Tennant of this deficiency in the Bank’s second motion for summary judgment, yet Pearson and Tennant failed to respond properly. See Schmidt v. McIlroy Bank & Trust, 306 Ark. 28, 811 S.W.2d 281 (1991). The Schmidts point to the testimony of their legal expert who testified Pearson and Tennant were negligent in waiting until the hearing on the summary judgment motion to request an amendment to the complaint. Pearson and Tennant countered with testimony from their own legal expert.
As a matter of law, attorneys are not liable for mistaken opinion on a point of law that has not been settled by a court of highest jurisdiction, and on which reasonable attorneys may differ. Cianbro Corp. v. Jeffcoat & Martin, 804 ESupp. 784 (D.S.C. 1992); Martinson Manufacturing Co., Inc. v. Seery, 351 N.W.2d 772 (Iowa 1984); Brown v. Gitlin, 19 Ill. App.3d 1018, 313 N.E.2d 180 (1974); Martin v. Burns, 102 Ariz. 341, 429 P.2d 660 (1967); Meagher v. Kavli, 97 N.W. 370 (Minn. 1959). As Pearson and Tennant point out, the disagreement between their legal expert and the Schmidts’ was sufficient evidence that, as a matter of law, Pearson and Tennant were not negligent in failing to amend the Schmidts’ complaint before the summary-judgment hearing. Further, they note this court’s split decision in Schmidt reflects that the issue was unsettled and reasonably subject to differing opinions among the *508experts. Accordingly, we conclude that the trial court here was within its authority to determine, as a matter of law, that Pearson and Tennant were not negligent in failing to amend the complaint before the summary-judgment hearing since whether Pearson and Tennant should have filed an amendment in these circumstances involved an unsettled legal issue over which experts could reasonably disagree.
Finally, the Schmidts contend it was negligent of Pearson and Tennant to request $1000 to appeal the foreclosure action when they had $4000 of the Schmidts’ money remaining in the attorneys’ trust accounts. Further, the Schmidts contend Pearson and Tennant were negligent in failing to appeal the foreclosure decree or, alternatively, return the $1000 to them. But as Pearson and Tennant point out, the issue of the $1000 is a contract issue and not one sounding in tort. Pearson also notes even if they had appealed the foreclosure decree, no evidence was presented at trial that the Schmidts would have prevailed and obtained reversal of the decree. Ultimately, the issue of the $1000 and appeal of the foreclosure decree is not a proximate cause of the Schmidts’ failure to prevail in their lender-liability action.
We hold the trial court was correct in finding no substantial evidence to support the verdict against Pearson and Tennant for legal malpractice. None of the issues presented by the Schmidts was the proximate cause of the loss of their lender-liability claim against the Bank. Therefore, attorneys Pearson and Tennant were entitled to judgment notwithstanding the verdict as a matter of law. Because of our holding, it is unnecessary to discuss the trial court’s alternative grant of a new trial based on questions of procedural irregularities. We affirm.
Jesson, C.J., Dudley and Newbern, JJ., not participating. Special Chief Justice CAROLYN B. WITHERSPOON joins this opinion. Special Justices HANI W. HASHEM and JOHN HARRIS JONES concur.