function initPage()
{
	var navRoot = document.getElementById("main-navigation");
	var lis = navRoot.getElementsByTagName("li");
	for (var i=0; i<lis.length; i++)
	{
		lis[i].onmouseover = function()
		{
			this.className = "hover";
			var divs = document.getElementsByTagName('div');
			for (var i = 0; i < divs.length; i++)
			{
				if (divs[i].className == 'opacity')
				{
					var correspUl = divs[i].parentNode.getElementsByTagName('ul')[0];
					divs[i].style.height = correspUl.offsetHeight + 'px';
				}
			}
		}
		lis[i].onmouseout = function()
		{
			this.className = "";
		}
	}
}

if (window.attachEvent && !window.opera)
	window.attachEvent("onload", initPage);
if (navigator.userAgent.indexOf("Gecko") != -1)
	window.addEventListener("load", initPage, false);