if ( document.getElementsByTagName ) {
var test=document.getElementById("nav");

var lis = test.getElementsByTagName("li");

for( var i in lis ) {
	if ( lis[i].className != null && lis[i].className.indexOf('hover') >= 0) {
            lis[i].onmouseover = function() {
                   this.className = "hover over";
            }
            lis[i].onmouseout = function() {
                   this.className = "hover";
            }
        }
}
}