function initNav()
{
    var nav = document.getElementById("nav");
    if(nav)
    {
        var lis = nav.getElementsByTagName("li");
        for (var i=0; i<lis.length; i++)
        {
            lis[i].onmouseover = function()
            {
                this.className += " hover";
            }
            lis[i].onmouseout = function()
            {
                this.className = this.className.replace(" hover", "");
            }
        }
    }
}
if (document.all && !window.opera) attachEvent("onload", initNav);