function RollOverImages() {
	this._Loaded = 0;
	this._restore_images = new Object;
	this._swap_images = new Object;
	for(var i=0;i<document.images.length;i++){
		img = document.images[i];
		if(img.name){
			this._restore_images[img.name] = new Image;
			this._swap_images[img.name]    = new Image;
			this._restore_images[img.name].src = img.src;
			this._swap_images[img.name].src = img.src.substring(0,img.src.length-4)+"_o"+img.src.slice(img.src.length-4);
		}
	}
	this._Loaded = 1;
	this.swap = function(str){
		if(this._Loaded)
			document.images[str].src = this._swap_images[str].src;
	}
	this.restore = function(str) {
		if(this._Loaded)
			document.images[str].src = this._restore_images[str].src;
	}
	return this;
 }