—Judgment, Supreme Court, Bronx County (Daniel FitzGerald, J.), rendered December 22, 1997, convicting defendant, after a jury trial, of criminal sale of a controlled substance in the third degree, and sentencing him, as a second felony offender, to a term of 8 to 16 years, unanimously affirmed.
The record fails to support defendant’s claim that he was deprived of his right to be present at sidebar conferences with prospective jurors. When, at the outset of jury selection, defendant invoked his right to be present for sidebar conferences, the court clearly instructed him that this request would be honored and that he should confer with his attorney any time he wished to attend any particular sidebar. Given the presumption of regularity that attaches to judicial proceedings (see, People v Harris, 61 NY2d 9, 16), we conclude from the record that, to the extent that defendant was absent from any sidebars, his absence was the result of his valid waiver of the right to be present.
Defendant’s claims that the court improperly received expert testimony concerning the roles of participants in a typical street-level drug sale, and that the expert witness was unqualified, are unpreserved (see, People v Tevaha, 84 NY2d 879, 881; People v Soto, 267 AD2d 15, lv denied 94 NY2d 925), and we decline to review them in the interest of justice. Were we to review these claims, we would find that the undercover officer was properly qualified as an expert on the basis of his training and experience, and that his brief testimony, carrying no suggestion of large-scale drug activity, was helpful to the jury in understanding the different roles of the participants in the instant sale (see, People v Kelsey, 194 AD2d 248).
We perceive no basis for reduction of sentence.
Defendant’s remaining contentions are unpreserved and we decline to review them in the interest of justice. Were we to review these claims, we would reject them. Concur — Nardelli, J. P., Tom, Andrias, Lerner and Marlow, JJ.