Stopping timed movies

1

if i have a randomClips function that shows a range of swf files every 15seconds and wanted to create a button that could stop the auto change of the clips, what would be the script for that button if the script for the randomClips looks like this:


randomClips = new Array("d+l A_news.swf", "maashaven B_news.swf", "maashaven A_news.swf", "gipsy A_news.swf", "gipsy B_news.swf", "d+l B_news.swf", "gw A_news.swf", "gw B_news.swf", "soundscapes A_news.swf", "soundscapes B_news.swf", "fhwsf A_news.swf", "fhwsf B_news.swf");
function randomBackground() {
	randomNumber = random(randomClips.length);
	loadMovie(randomClips[randomNumber], "_root.mtClip");
}
randomBackground();
timeLimit = 15000;
// for example 15 seconds
startTime = getTimer();
actualTime = getTimer();
function timerReload() {
	if (actualTime-startTime<=timeLimit) {
		actualTime = getTimer();
	} else {
		randomBackground();
		startTime = getTimer();
	}
}
// creating an empty movie clip so I can use it's onEnterFrame event
this.createEmptyMovieClip("emptyClip", 1);
emptyClip.onEnterFrame = timerReload;

thanks.
jonathan