A Chatham County jury found Edward Devoun Johnson guilty of two counts of selling cocaine. On appeal, Johnson challenges the sufficiency of the evidence introduced against him, as well as the admission of similar transaction evidence and impeachment evidence. We affirm Johnson’s conviction.
1. The evidence was sufficient to support the guilty verdict. The State produced testimony from two undercover police officers who identified Johnson as the person who sold them suspected cocaine on two occasions. A chemist from the State Crime Lab testified that he tested the substance involved in each sale, and the substances tested positive for cocaine. Further, the State produced similar transaction evidence that Johnson had previously sold cocaine to another undercover police officer about a block away from the present sales.
In considering an appeal from a criminal conviction, this Court does not weigh the evidence or determine the credibility of witnesses but only determines whether the evidence viewed in the light most favorable to the guilty verdict was sufficient to support the conviction. Parker v. State, 220 Ga. App. 303 (469 SE2d 410) (1996). The evidence was sufficient for the jury to conclude beyond a reasonable doubt that Johnson was guilty of both sales of cocaine. Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560) (1979).
2. As evidence of a prior similar transaction, the trial court admitted testimony from a former undercover police officer that in *302December 1987, Johnson sold cocaine to him about a block from the present sales. As part of the similar transaction evidence and over defense counsel’s objection, the trial court admitted documentary evidence of Johnson’s first offender guilty plea to the 1987 offense.
After the evidence was presented to the jury, the trial court subsequently reversed its ruling on the admissibility of the first offender plea and ruled that it was not admissible into evidence. At the request of defense counsel, the trial court gave curative instructions to the jury explaining the nature of first offender treatment and instructing the jurors that Johnson’s first offender plea to the offense was not a conviction and that it was not to be considered by the jury in any way in connection with the case. The trial court told the jurors that they could consider the testimony relating to the circumstances of Johnson’s prior conduct. After giving the requested curative instruction, the trial court asked defense counsel if any further instruction was requested and defense counsel responded in the negative.
Johnson contends on appeal that the trial court’s curative instruction was insufficient to cure the error and ensure him of a fair trial.
Testimony concerning the circumstances of the prior similar transaction was properly admitted; however, it was error to admit Johnson’s first offender guilty plea as evidence that he committed the prior similar offense. Tilley v. State, 197 Ga. App. 97 (397 SE2d 506) (1990); Davis v. State, 269 Ga. 276 (496 SE2d 699) (1998). Nevertheless, the trial court corrected the error and gave the jury curative instructions requested by defense counsel. No motion for a mistrial was made, and defense counsel indicated satisfaction with the curative instructions. Because defense counsel acquiesced in the curative instructions, made no renewed objection or mistrial motion, and stated no other action he desired the court to take, this enumeration presents nothing for appellate review. Fann v. State, 254 Ga. 514, 517 (331 SE2d 547) (1985).
3. Johnson challenges as reversible error the introduction for impeachment purposes of a 1975 guilty plea for the offense of misdemeanor theft by shoplifting. Johnson contends that the State failed to prove that he is the “Edward Johnson” named in the prior guilty plea. This enumeration of error is meritless for the following reasons.
(a) When asked if he had objection to the introduction of the shoplifting conviction for impeachment purposes, the defense attorney stated “I do, Your Honor. I don’t believe there’s been a proper foundation laid.” That was all. The trial court reserved ruling, and the defense attorney did not raise further objection at the time of ruling.
It has long been the law that “ ‘[objection on the ground of a lack *303of proper foundation without stating what the proper foundation should be is insufficient and presents nothing for consideration on appeal.’ ” (Emphasis supplied.) Gordon v. State, 206 Ga. App. 450, 455 (4) (b) (425 SE2d 906) (1992); Adams v. State, 264 Ga. 71, 74 (440 SE2d 639) (1994).1 Here, the defense attorney never stated why the foundation was allegedly defective and “what the proper foundation should be” so as to preserve this issue for appeal. Accordingly, under the law, Johnson’s enumeration of error regarding the introduction of his prior conviction for shoplifting presents nothing for our consideration on appeal. Id.
(b) However, even assuming arguendo that this claim of error is properly before us, it remains meritless. The rule with regard to the introduction of a prior conviction for impeachment purposes is that “[if] the witness testifies positively and unequivocally under oath that he was never indicted, tried, convicted, or sentenced for the offense therein charged in the county from which the certified record comes, [then] the presumption arising solely from the identity of names is overcome,” and the State must offer further proof. (Emphasis supplied.) Robinson v. State, 209 Ga. 650, 651 (4) (75 SE2d 9) (1953).2
At trial, Johnson testified that he had serious memory problems due to “anxiety reaction” stemming from the Vietnam war. Accordingly, under such facts, Johnson’s assertions “I don’t know anything about this” and “Shoplifting? No, I never shoplift before[,]” can hardly be considered a “positive and unequivocal” denial of his identity as the “Edward Johnson” named in the 1975 Chatham County indictment, guilty plea, and sentence for shoplifting so as to rebut the State’s prima facie showing. In that regard, Johnson also denied any knowledge of: the incident for which he was on trial; his 1987 prior conviction for selling drugs (introduced as a similar transaction); and the prior 1975 conviction for shoplifting. Such blanket denials in the face of purported memory loss made the issue of Johnson’s identity one for the jury, not a basis for reversal by this Court.
Further, concordance of name was not the sole proof of identity so as to trigger the rule in Robinson v. State, supra, as cited above. There was also concordance of location between the prior offense and Johnson’s locale at the time of the offense (Savannah), and similarity of age in 1975 (27-28 years old). Thus, Johnson’s mere denial that he was the person named in the indictment did not rebut the State’s *304prima facie showing. Under the circumstances of this case, there must be a denial and proof to the contrary. Hammond v. State, 139 Ga. App. 820, 822-823 (229 SE2d 685) (1976); Hill v. State, 162 Ga. App. 637, 638 (292 SE2d 512) (1982); Glass v. State, 181 Ga. App. 448 (352 SE2d 642) (1987). Without such proof, there was no error in the admission of the prior conviction for whatever weight the jury wished to assign it.
(c) Finally, “[t]he proper test to determine whether error is harmless (due to overwhelming evidence of guilt) is not whether there is sufficient other evidence to convict but whether it is highly probable that the error did not contribute to the judgment. Ragan v. State, 264 Ga. 190, 192 (3) (442 SE2d 750) [(1994)].” (Citations and punctuation omitted.) Letlow v. State, 222 Ga. App. 339, 343 (474 SE2d 211) (1996).
Here, the State presented the testimony of two undercover police officers to whom Johnson had made the 1994 hand-to-hand crack cocaine sales that are the subject of the instant appeal. The officers positively identified Johnson as the seller. In addition, the State presented similar transaction testimony from an undercover police officer who positively identified Johnson as the person who sold him crack cocaine in 1987. Both the 1987 sale and 1994 sales occurred at the same location, next to Johnson’s home at 263 Ferrell Street in Savannah, and, in both instances, intermediaries took the undercover officers to Johnson, who was holding the crack cocaine.
At trial, the defense was alibi. Johnson called as witnesses three men who work as mechanics for Johnson in the backyard of his home, which also serves as a car servicing lot; they each testified that they worked in the car yard on the date of the cocaine sales and that Johnson was at home with a “bad back” on that day. However, factually, the record shows that the alibi could not be sustained.
Witness Harry Mitchell could not remember for which day he was supposed to provide the “bad back” alibi: “October 15? Is that the day that I was supposed to been in the yard, that day?” He also testified that “I don’t exactly know what happened that day. I was under the car.” Witness Frank Hayes testified that he left Johnson’s house at dusk because he could not work on cars in the dark and that it would have been dark by 9:45 p.m. The cocaine sales occurred at 9:45 p.m. Johnson’s last witness, James Cohen, stated that he, too, left Johnson’s car yard at approximately 8:30 to 9:00 p.m., well before the 9:45 p.m. cocaine sales occurred.
Johnson took the stand, as well, and testified on his own behalf. He testified only that “in the middle of September,” 1994, he suffered a muscle spasm in his back; no other time frame in relation to the incident date was given, and Johnson did not testify that his bad back incapacitated him. Johnson further stated that all of the officers *305who testified against him lied on the stand under oath and committed perjury. He testified that he “couldn’t say why” the officers were lying and that he had no evidence of a police conspiracy against him, but that “sometime it happens.”
In light of the overwhelming evidence of Johnson’s guilt, including eyewitness testimony regarding Johnson’s sale of cocaine to undercover police officers, his prior conviction for sale of cocaine to an undercover police officer, as well as the lack of a viable defense, the admission of a 20-year-old misdemeanor shoplifting conviction, if error at all, was harmless. Morrison v. State, 225 Ga. App. 710 (484 SE2d 762) (1997); Letlow v. State, supra at 343. A review of the record shows that Johnson’s own testimony and that of his witnesses did more to undermine his credibility than the admission of limited evidence of a 1975 misdemeanor conviction which was totally unrelated in any fashion to the charges against him. It is highly probable that such misdemeanor conviction did not contribute to the judgment. Id.
Judgment affirmed.
McMurray, P. J., Johnson, P. J., Blackburn, Smith, JJ., and Senior Appellate Judge Harold R. Banke concur. Andrews, C. J., dissents.Generally, this Court does not cobble together the trial testimony of the defendant, an insufficient objection raised by the defense attorney, and the subjective understanding of the trial court in order to fashion a preserved issue for appeal based upon “the context of the proceedings,” as advocated by the dissent herein.
But see Wyley v. State, 169 Ga. App. 106, 109 (3) (311 SE2d 530) (1983), where an unusual name may provide a sufficient basis for admission, even when the defendant “positively and unequivocally” denies he is the person named in the prior conviction.