// JavaScript Document
var Rollover = {
	
	r_over: "_r.",
	r_out: ".",
	imgformat: "jpg",
	
	init: function(invoke){
		var mainmenus = $$(invoke);
		mainmenus.invoke('observe', 'mouseover', Rollover.rollover);
		mainmenus.invoke('observe', 'mouseout', Rollover.rollover);
	},
	
	rollover:function(ev){
		
		//var end = (ev.type == "mouseover") ? Rollover.r_over : Rollover.r_out;
		//var endlength = (ev.type == "mouseover") ? Rollover.r_out.length : Rollover.r_over.length;
		
		var target = ev.element().src;
		var ro = target.indexOf("_r");
		
		var end = (ro == -1) ? Rollover.r_over : Rollover.r_out;
		var endlength = (ro != -1) ? Rollover.r_over.length : Rollover.r_out.length;
		
		//das muss hier anders gehen, nicht explizit mit jpg oder png
		/*var begin = target.indexOf(".jpg") + 1;
		if(!begin){
			begin = target.indexOf(".png") + 1;
		}*/
		var format = target.substring(target.length - 3, target.length);
		/*alert(f);
		var formatlength = target.length;
		var format = target.substring(begin, formatlength);*/
		
		var length = target.length - endlength - format.length;
		var bigimg = target.substring(0, length);
		
		ev.element().src = bigimg + end + format;
		//alert(ev.element().src);
	}
}