data SAMPLE(drop = i j count); count = 0; array sel_obs(100) _temporary_; do i = 1 to 100; redo: select = ceil(ranuni(0)*total); do j = 1 to count; if sel_obs(j) = select then goto redo; end; set POP point=select nobs=total; count = count + 1; sel_obs(count) = select; output; end; stop; run;