// shows submenu when mainitem is clicked
function showSub(which) {
	if( which ) {
				
		// expand submenulist
		if(document.getElementById(which).childNodes[2]){
			document.getElementById(which).childNodes[2].style.display = 'block';
		}
		// set style of this item active
		document.getElementById(which).childNodes[0].childNodes[0].className = 'activemain';
		
	}
}