$(document).ready(function() { 
		$("ul.subnav").parent().mouseenter(function() {
			$(this).find("ul.subnav").fadeIn("slow"); 		
		}).mouseleave(function() {
			$(this).find("ul.subnav").hide();
		});
	});
	
	function setcurrentnavi(num) {
		if (num != "") {
			var navibutton = $("ul.topnav").find("#navi" + num);
			$(navibutton).removeClass("rollover");
			$(navibutton).attr("src", $(navibutton).attr("src").replace("_off","_on"));	
		}
		
		$("img.rollover").load(function() {
			var cacheImage = document.createElement('img');
			cacheImage.src = this.src.replace("_off","_on");
		});
		
		$("img.rollover").hover(function() {
        	this.src = this.src.replace("_off","_on");
 		}, function() {
  			this.src = this.src.replace("_on","_off");
 		});
	};