function horizontal() 
{
   var navItems = document.getElementById("menu_dropdown").getElementsByTagName("li");
   for (var i=0; i< navItems.length; i++) 
   {
      if((navItems[i].className == "submenu")||(navItems[i].className == "submenuActive"))      
      {
         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";
            }
            navItems[i].onclick=function() 
            {
            	this.getElementsByTagName('ul')[0].style.display="none";
            }
         }
      }
   }
 
}