if you want to use while scripts safely put a "or cap" on it.
something like this
wcount=0
while ("put condition here" or wcount>100) {
wcount>=100 ? trace("its laggeh") : wcount++
//put your scripts here.
}
STILL SAVE BEFORE RUNNING IT!!! just incase you typed something wrong or something goes horribly horribly wrong. it just helps a LOT for testing and you can probably remove it or make the wcount higher when youre done. and even with no while testing still save before testing anything at all. and regularly make backup FLA files incase something gets corrupted (ive lost lots because of file corruption)