Brian-- Thank you for acknowledging my suggestions and trying them. Let's make sure we're talking about the same thing here. Let's say you compiled and ran your interpreter, then inputted a program like this: PRINT "1" PRINT "2" PRINT "3" PRINT "4" PRINT "5" PRINT "6" PRINT "7" PRINT "8" PRINT "9" PRINT "10" PRINT "1" PRINT "2" PRINT "3" PRINT "4" PRINT "5" PRINT "6" PRINT "7" PRINT "8" PRINT "9" PRINT "10" And then while it's running, merrily printing 1,2,3,4,5,etc., you press command-. Does it stop? Is that what you're wanting to accomplish? I tried compiling your code, and couldn't come close, sorry. But I added my suggestions to Stu's compiler, inputted the program above into the window, hit command-R, and then pressed command-., and the run stopped. Note that I also added a DIM statement for gRunning, something I didn't mention before that I figured you ought to already know. So I know my suggestion works. Posting a huge cut/paste block of code that won't compile is really pointless. You might as well not do it. I've said it before, I'll say it again, no one wants to debug someone else's code. Not in school? How much programming experience? --Steve On 8/27/05 8:08 PM, "Brian Heibert" <bheibert@...> wrote: > I tried adding those things to it... > but the break wouldn't happen > when does it happen command-period??