function RollOver () {
	var buttons = [];
	this.ok=false;
	for (var i=0; i<arguments.length; i++) {
		buttons[buttons.length]=[arguments[i][0],arguments[i][1]];
		buttons[buttons.length-1][2] = new Image;
		buttons[buttons.length-1][2].src = buttons[i][0];
	
		buttons[buttons.length-1][3] = new Image;
		buttons[buttons.length-1][3].src = buttons[i][1];
	}
	this.ok=true;

	this.switchthis=function (obj) {
		if  (this.ok==false) {
			return;
		}
		if (document.images) {
			var str=obj.src;
			for (var i=0; i<buttons.length; i++) {
				if (str.indexOf(buttons[i][0])>-1) {
					obj.src=buttons[i][3].src;
				}
				if (str.indexOf(buttons[i][1])>-1) {
					obj.src=buttons[i][2].src;
				}
			}
		}
	}
	return this;
}