var change;
var image;
var i=1;

function changePic(thumbdir,numberOfThumbnails)
{
    if(window.i > numberOfThumbnails) window.i=1;
		
    var imageSource=thumbdir+"/thumb"+i+".jpeg";
	window.image.src=imageSource;
    window.i++;
}

function startChange(image,thumbdir,numberOfThumbnails,time)
{	
	window.image=image;
	window.i=1;
	var funcString="changePic('"+thumbdir+"',"+numberOfThumbnails+")";
	window.change=window.setInterval(funcString,time);
}

function endChange(image,thumbnail)
{	
    window.clearInterval(window.change);
	var imageSource=thumbnail;
	image.src=imageSource;
}