var timeout	= 0;
var closetimer = 0;
var ddmenuitem = false;

// open hidden layer
function mopen( id ) {
	// cancel close timer
	mcancelclosetime();

	// close old layer
	if( ddmenuitem ) {
		ddmenuitem.style.visibility = 'hidden';
	}

	// get new layer and show it
	ddmenuitem = document.getElementById( id );
	ddmenuitem.style.visibility = 'visible';
}

// close showed layer
function mclose() {
	if( ddmenuitem ) {
		ddmenuitem.style.visibility = 'hidden';
	}
}

// go close timer
function mclosetime() {
	closetimer = window.setTimeout( mclose, timeout );
}

// cancel close timer
function mcancelclosetime() {
	if( closetimer ) {
		window.clearTimeout( closetimer );
		closetimer = null;
	}
}

// close layer when click-out
// document.onclick = mclose;