function buildsubmenu(){
var ultags=document.getElementById("mainNaviList").getElementsByTagName("ul")
for (var t=0; t<ultags.length; t++){
	ultags[t].style.top=125+ultags[t].parentNode.offsetHeight+"px" //dynamically position first level submenus to be height of main menu item
	ultags[t].parentNode.onmouseover=function(){
		this.getElementsByTagName("ul")[0].style.visibility="visible"
	}
	ultags[t].parentNode.onmouseout=function(){
		this.getElementsByTagName("ul")[0].style.visibility="hidden"
	}
}
}