var myUl=document.getElementById("nav_ul").getElementsByTagName("ul");
	var myLi=document.getElementById("menu_li").getElementsByTagName("li");
	var j=myUl.length;
	var k=myLi.length;
	for (i=0;i<j;i++){
	myUl[i].onmouseover=function(){
	this.style.display="block";
	}
	//myUl[i].onmouseout=function(){
	//this.style.display="none";
	//}
	}
	function showUl(m,n){
	for(x=0;x<j;x++){
	myUl[x].style.display="none";
	}
	myUl[n].style.display="block";
	myUl[n].style.left=m;
	
	}
	function hideUl(n){
	myUl[n].style.display="none";
	}
	function changeMenubg(t){
		for(y=0;y<k;y++){
	     myLi[y].style.background.src="images/navbg.jpg";
	    }
		<!--myLi[t].style.background="#F9F9F9";   -->
	}
	showUl(45,0);