function dropdown_subs(dropmenu){
	if(typeof myTimer != 'undefined'){
		clearTimeout(myTimer);
	}
	// loop all dropdown menus and hide them
	document.getElementById('dropdown_aboutus').style.display="none";
	document.getElementById(dropmenu).style.display="";
	starttimer(dropmenu);
}


function dropdown_hide(dropmenu){
	document.getElementById(dropmenu).style.display="none";
}

function starttimer(dropmenu){
	myTimer = setTimeout("dropdown_hide('"+dropmenu+"')",2500);
}