function initNav(){
    if ( document.getElementById )
    {
        var nav = document.getElementById('menu');
        var navlis = nav.getElementsByTagName('li');
        
        for ( var i=0; i<navlis.length; i++ )
        {            
            if ( navlis.item(i).getElementsByTagName('ul')[0] )
            {
				addAnEvent(navlis.item(i),'keyup',visible);
                addAnEvent(navlis.item(i),'mouseover',visible);
                addAnEvent(navlis.item(i),'mouseout',hidden);
                addAnEvent(navlis.item(i),'blur',hidden);
                addAnEvent(navlis.item(i),'focus',visible);
            					
				var navlisul = navlis.item(i).getElementsByTagName('ul');
			}
        }
		

	}
}


function addAnEvent( target, eventName, functionName){
        eval('target.on'+eventName+'=functionName');
}

function hidden(){
	this.getElementsByTagName('ul')[0].className = "";
}

function visible(){

    this.getElementsByTagName('ul')[0].className = "block";
}
        
window.onload=initNav;