function horizontal() {
 
   var navItems = document.getElementById("menu_dropdown").getElementsByTagName("li");
	
   for (var i=0; i< navItems.length; i++) {
	  if(navItems[i].className == "submenu")
	  {
		 if(navItems[i].getElementsByTagName('ul')[0] != null)
		 {
			navItems[i].onmouseover=function() {this.getElementsByTagName('ul')[0].style.display="block";}
			//navItems[i].onmouseout=function() {this.getElementsByTagName('ul')[0].style.display="none";this.style.backgroundColor = "#fff";}
			navItems[i].onmouseout=function() {this.getElementsByTagName('ul')[0].style.display="none";}
		 }
	  }
   }
 
}