function IEHoverPseudo() {

	var navItems = document.getElementById("ul_menu").getElementsByTagName("li");
	
	for (var i=0; i<navItems.length; i++) {
		if(navItems[i].className == "") {
			navItems[i].onmouseover=function() { this.className += " over"; }
			navItems[i].onmouseout=function() { this.className = ""; }
		}
	}

}
window.onload = IEHoverPseudo;

function blocking(nr)
{
	if (document.getElementById)
	{
		vista = (document.getElementById(nr).style.display == 'none') ? 'block' : 'none';
		document.getElementById(nr).style.display = vista;
	}
}