The appellants, a mother and daughter, were found guilty of shoplifting merchandise with an aggregate value in excess of $100, see OCGA 16-8-14 (b) (2), and also of shoplifting merchandise with an aggregate value of less than $100. See OCGA 16-8-14 (b) (1). They appeal from the denial of their motion for new trial. Held:

1. The evidence, considered in its entirety, was sufficient to enable a rational trier of fact to find the appellants guilty on both counts of the indictment beyond a reasonable doubt. See generally Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560) (1979).

2. The appellants contend that the trial court failed to give adequate instructions to the jury regarding impeachment of witnesses. Pretermitting whether any of the state's witnesses made any prior inconsistent statements, it does not appear that the appellants requested any instructions on this issue as required by OCGA 5-5-24 (b). A criminal defendant is relieved of the duty to request instructions only "in those circumstances where the omission is clearly harmful and erroneous as a matter of law in that it fails to provide the jury with the proper guidelines for determining guilt or innocence." Spear v. State, 230 Ga. 74, 75 (195 SE2d 397) (1973). In the present case, the trial court gave a general charge on credibility of witnesses which adequately covered the legal principles at issue. Consequently, this enumeration of error establishes no ground for reversal.