Brandon, Thanks for helping. Here's what I did, which seems to be a simplified version of your program. Still doesn't work. I run programs by pressing F8 and Ctrl-F8. The '>' represents the command prompt. > x = 1 > x = 2 Opened new source file and entered the following: z = x + y   delvar   , x delvar   , y print   , z end Saved file as mytest. > .run mytest Console report: % Compiled module: $MAIN$. % Active main program terminated by call to DELVAR. Do you see the problem? Steve  

Wow, that didn't come out right. Let me try again. > x = 1 >x = 2 Opened new source code file. Entered: ; --------------------------------------------- ; start code z = x + y delvar, x delvar, y print, z end ; end code ; --------------------------------------------- Saved file as "mytest". Entered at command line: .run mytest Console message: % Compiled module: $MAIN$ %Active main program terminated by call to DELVAR Why is a main program being terminated by calling DELVAR? I thought that main programs were the one place where DELVAR could be used? Thanks. Steve