var interval = 1000;
var obj_index = 0;
var delay = 4;
var objects = new Array();

function callback(numOfObjects)
{
	if (delay < 4)
	{
		delay = delay + 1;
		return;
	}
	delay = 0;
	objects[obj_index].roll();
	obj_index =  (obj_index + 1) % numOfObjects;
}

function iroll(images_, id__, numberOfImages_)
{
	this.index = 0;
	this.numberOfImages = numberOfImages_;
	this.id_ = id__;
	this.images = images_;
	this.roll = roll;

}

function roll()
{
	this.index = (this.index + 1) % this.numberOfImages;
	var i = returnObjById(this.id_);
	i.src = this.images[this.index];

}

function returnObjById( id )
{
    if (document.getElementById)
        var returnVar = document.getElementById(id);
    else if (document.all)
        var returnVar = document.all[id];
    else if (document.layers)
        var returnVar = document.layers[id];
    return returnVar;
}