window.onload=initmenu;

function initmenu() {
   var menunumber = 0;
   menulist = document.getElementById("nav");
   menuopts = menulist.getElementsByTagName("li");
   for (var i = 0; i < menuopts.length; i++) {
       if ( menuopts[i].childNodes.length > 2 ) {
	  	 	 menunumber = menunumber + 1;
			 menuopts[i].className = "top";
			 menuopts[i].childNodes[2].className = "submenu";
			 menuopts[i].childNodes[2].id = "menu" + menunumber;
	  	 	 eval("menuopts[" + i + "].onmouseover = function(){showMenu(" + menunumber + ");}");
			 eval("menuopts[" + i + "].onmouseout = function(){showMenu(" + menunumber + ");}");
	  }
   }
}

function showMenu(menuNo) {
		 if (document.getElementById("menu" + menuNo).style.display == 'block') {
		 document.getElementById("menu" + menuNo).style.display = 'none';
		 } else {
		 document.getElementById("menu" + menuNo).style.display = 'block';
		 }
}