FOR <var> = <start> TO <end> [STEP <stepval>]
<var> is the name of the var to track the value (Incremented on NEXT)
<start> is the value assigned to the named variable the first time through.
<end> is the value <var> is compared against on "next" - if it's greater, ActionScript continues AFTER the NEXT
<stepval> is an optional increment (or decrement, if <start> is greater than <end>) on each NEXT
BREAK skips to the appropriate NEXT and exits the loop prematurely.
So that's FOR/NEXT operation in a nutshell. It should clean up code nicely...
Pretty straightforward... put subroutines in your script, stay "local" with variables and such. On "RETURN" the script will return to the line AFTER the GOSUB.
There you go. I might do DO/WHILE if I get around to it....