Step through code?

I’ve got a class with a timer that moves a dot from one place to another and, depending on where it starts and where it ends up, it’s doing weird things – suddenly halting and jumping around instead of proceeding. Is it possible for me to set up Flash to step through execution of the code so that I can see what the actionscript is “thinking” when it gets to the point where it goes wacky? (I won’t post the code unless someone wants to see it – it’s very long and it would put you to sleep.)

Thanks,
Tim