function initNav() {
		var navRoot = document.getElementById("header-nav");
		var lis = navRoot.getElementsByTagName("li");
		for (var i=0; i<lis.length; i++)
		{
			var drops = lis[i].getElementsByTagName("ul");
			if (drops.length)
			{
				lis[i].onmouseover = function()
				{
					this.className += " hover";
				}
				lis[i].onmouseout = function()
				{
					this.className = this.className.replace("hover", "");
				}
			}
		}
}

if (window.addEventListener){
	window.addEventListener("load", initNav, false);
}
else if (window.attachEvent){
	window.attachEvent("onload", initNav);
}

//two popup functions used in the teaching zoo photo galleries
//this is none accessible, should be deprecated to use only omni pages
function popUp2(URL) {
day = new Date();
id = day.getTime();
eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=620,height=470,left = 200,top = 0');");
}
function popUp(URL) {
day = new Date();
id = day.getTime();
eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0,width=520,height=420,left = 200,top = 0');");
}