Judgment, Supreme Court, New York County (Nicholas Figueroa, J.), rendered September 7, 1990, convicting defendant, after a jury trial, of criminal sale of a controlled substance in the third degree and criminal possession of a controlled substance in the seventh degree, and sentencing him to concurrent prison terms of AV2 to 9 years, and six months, respectively, unanimously affirmed.
Defendant, who was convicted of selling one $10 glassine envelope of cocaine to an undercover officer and possessing two other glassine envelopes of heroin, was not unfairly prejudiced by the admission of background evidence concerning the procedures used in connection with undercover street-level purchases (People v Martinez, 179 AD2d 501, lv denied 79 NY2d 1051; People v Almodovar, 178 AD2d 133, lv denied 79 NY2d 943; People v Colon, 172 AD2d 173, affd 78 NY2d 998). Further, in light of the overwhelming evidence of guilt,