OPINION

A jury found George Walker guilty of the sale of a controlled substance (heroin), in violation of NRS 453.321. Since this was his second conviction for the sale of heroin, Walker was sentenced to life imprisonment in the Nevada State Prison without possibility of parole, as mandated by NRS 453.321. Walker has appealed from his judgment of conviction, seeking reversal on several grounds, which we reject[*726] as meritless; therefore, we affirm the judgment of the lower court.

On February 23, 1973, Wiffiani Arnold, an undercover narcotics agent for the State of Nevada, approached one Johnny Benson in the Brown Derby bar in Las Vegas, seeking to purchase heroin. After some preliminary discussion, Benson took Arnold to meet Walker, and Arnold purchased from Walker a balloon containing heroin, for $30. Walker took the stand and denied the sale.

Walker claims on appeal that the evidence was insufficient to support the jury's verdict. The rule is well established that it is the function of the jury, not the appellate court, to weigh the evidence and pass upon the credibility of the witness. A verdict supported by substantial evidence may not be disturbed on appeal. Apparently the jury believed Arnold rather than Walker, which was their prerogative. "Where there is substantial evidence to support a verdict in a criminal case, as the record indicates exists in this case, the reviewing court will not disturb the verdict nor set aside the judgment." Sanders v. State, 90 Nev. 433, 434, 529 P.2d 206, 207 (1974). See also Azbill v. State, 88 Nev. 240, 495 P.2d 1064 (1972); Cross v. State, 85 Nev. 580, 460 P.2d 151 (1969).

Walker also complains that the district judge erred in refusing a continuance of the trial on the date it had started, for the purpose of subpoenaing Johnny Benson, who was incarcerated in the State Prison, to testify in Walker's behalf. The record shows that Walker's attorney did not wish to call Benson, although he made Walker's views known to the trial judge. ^[1] No subpoena had been issued for Benson, nor a motion[*727] for continuance made, as provided in DCR 21. See Hill v. Sheriff, 85 Nev. 234, 452 P.2d 918 (1969). There is no merit to Walker’s contention.

Walker also asserts that, because of the State’s failure to establish a proper chain of custody, the trial court committed error in admitting in evidence the heroin. Arnold testified that he placed the balloon containing the heroin that he purchased from Walker, in his glass case, and then put it in a State narcotics evidence envelope, which he deposited in the evidence impound at the State Narcotics Division office in Las Vegas; that he personally hand-delivered the proposed exhibits to the justice court, where they were received in evidence at the preliminary hearing. Richard Russell Renner, a chemist with the Las Vegas Metropolitan Police Department, testified that he removed the above-named exhibits from the county clerk’s office for laboratory testing a few days before the district court trial and then returned the exhibits to the clerk. No objection was made at the time the exhibits relating to the balloon and heroin were received in evidence. Earlier in the trial, defense counsel had stated to the court that he would have no objection to the admission of the exhibits if a proper chain of custody from the time of arrest were established. Apparently counsel was satisfied, for he made no objection when the[*728] exhibits were formally offered. A review of the record demonstrates a proper showing of a chain of custody of the evidence received. See Sorce v. State, 88 Nev. 350, 497 P.2d 902 (1972); Ricci v. State, 91 Nev. 373, 536 P.2d 79 (1975).

Finally, Walker argues that he was denied due process because of the inadequacy of his counsel. We find this charge completely without merit.

Affirmed.