var max = 16;
var timeoutID;
var imgnr = 0;
function changeimage(thisimg, dirid, videoid) {
	videoid = zerofill(videoid, 7);
	dirid = zerofill(dirid, 7);
	if(imgnr == max) imgnr = 0;
	imgnr++;
	imgnr = zerofill(imgnr, 3);
	thisimg.src = 'http://thumbs.redtube.com/_thumbs/' + dirid + '/' + videoid + '/' + videoid + '_' + imgnr + '.jpg';
	timeoutID = setTimeout(function(){changeimage(thisimg, dirid, videoid)}, 400);
}
function stopchange(thisimg, dirid, videoid) {
	videoid = zerofill(videoid, 7);
	dirid = zerofill(dirid, 7);
	clearTimeout(timeoutID);
	thisimg.src = 'http://thumbs.redtube.com/_thumbs/' + dirid + '/' + videoid + '/' + videoid + '_001.jpg';
	imgnr = 0;
}
function zerofill(number, countzero) {
	var number = "" + number; 
	while(number.length < countzero) number = "0" + number; 
    return number;
}