function addOnLoad(func) {
	var oldonload = window.onload;

	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function() {
			oldonload();
			func();
		}
	}
}

//==================== CSS drop menu
function activateMenu() {  

	nav = document.getElementById('menu_nav');  
	if (document.all && nav.currentStyle) {    
	    var navroot = nav;
	    var lis=navroot.getElementsByTagName("LI");  
	    for (i=0; i<lis.length; i++) {
	        if(lis[i].lastChild.tagName == "UL"){
	         	lis[i].onmouseover = function() {this.lastChild.style.left="auto"; }
	            lis[i].onmouseout=function()    {this.lastChild.style.left="-999em";}
	        }
	    }
	}
}
addOnLoad(activateMenu);