Hi, suppose we have series and want to add values to some observations. Following script doesn't work: <script> nulldata 120 series y = normal() loop for (i=1; i<=109; i+=12) genr y[$i] += 1000 endloop </script> but this one works fine: <script> nulldata 120 series y = normal() scalar j = 0 loop for (i=1; i<=109; i+=12) j = $i genr y[j] += 1000 endloop </script> Marcin -- Marcin Błażejowski http://www.wrzosy.nsb.pl/~marcin/ GG# 203127