its because (more or less) you have TWO variables called introPlayed.
one on the MAIN timeline..and one in the movieClip timeline.
you can either add _root (or whatever path) to the variable in movieClip (_root.introPlayed = true or better yet..just set it with the button once you have pressed it.
maybe like this:
PHP Code:
button1.onRelease = function() {
_root.main_mc.gotoAndStop("phone");
gotoAndStop("phone");
if (introPlayed == true) {
_root.main_mc.phone_mc.phonesub_mc.gotoAndStop("in troplayed");
//end frame of movieclip
} else {
introPlayed = true;
}
};