var timeout	= 500;
var closetimer	= 0;
var ddmenuitem	= 0;
var ddmenuhead	= 0;


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

		
	// get new layer and show it
	ddmenuitem1 = document.getElementById('m1');
	ddmenuitem2 = document.getElementById('m2');
	ddmenuitem3 = document.getElementById('m3');
	ddmenuitem4 = document.getElementById('m4');
	
	if(ddmenuitem1 != null && ddmenuitem2 != null && ddmenuitem3 != null && ddmenuitem4 != null) {
		ddmenuitem1.style.visibility = 'visible';
		ddmenuitem2.style.visibility = 'visible';
		ddmenuitem3.style.visibility = 'visible';
		ddmenuitem4.style.visibility = 'visible';
	}
}
// close showed layer
function mclose(id) {
	if(ddmenuitem1 != null && ddmenuitem2 != null && ddmenuitem3 != null && ddmenuitem4 != null) {
		ddmenuitem1.style.visibility = 'hidden';
		ddmenuitem2.style.visibility = 'hidden';
		ddmenuitem3.style.visibility = 'hidden';
		ddmenuitem4.style.visibility = 'hidden';
	}
}

// go close timer
function mclosetime(id) {
	if (document.getElementById(id).style.backgroundImage != "url(/objects/images/nav_" + id + "_active.gif)") {
		document.getElementById(id).style.backgroundImage = "url(/objects/images/nav_" + id + ".gif)";
	}
	closetimer = window.setTimeout(function(){mclose(id);}, timeout);
}

// cancel close timer
function mcancelclosetime(id) {
	if (document.getElementById(id).style.backgroundImage != "url(/objects/images/nav_" + id + "_active.gif)") {
		document.getElementById(id).style.backgroundImage = "url(/objects/images/nav_" + id + "_hover.gif)";
	}
	if(closetimer) {
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}

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