//this code is an adaptation from code found at http://javascript-array.com/scripts/simple_drop_down_menu/
//for a simple drop down menu

var time =500;
var timer=0;
var ddmenuitem=0;

function dd_open(id){
	dd_cancel_close();
	dd_hard_close();
	
	ddmenuitem = document.getElementById(id);
	ddmenuitem.style.visibility = 'visible';
}
function dd_hard_close(){
	if (ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}
function dd_close(){
	timer = window.setTimeout(dd_hard_close, time);
}
function dd_cancel_close(){
	if(timer){
		window.clearTimeout(timer);
		timer = null;
	}
}

document.onclick = dd_close;