function imgSwap(pic)
{
	var path = pic.src;
	var overState = "_hot";
	var imgStr, hover, type;
	
	if(path.indexOf(".gif") != -1) {
		type = ".gif";
		imgStr = path.substring(0, path.indexOf(type))
		hover = imgStr + overState + type;
	} else if(path.indexOf(".jpg") != -1) {
		type = ".jpg";
		imgStr = path.substring(0, path.indexOf(type))
		hover = imgStr + overState + type;
	} else {
		alert("Unsupported Image Format.");
		type = hover = null;
		pic.onmouseover = null;
		return;
	}
	
	pic.src = hover;
	
	pic.onmouseout = function() {
		path = this.src;
		imgStr = path.substring(0, path.indexOf(overState + type))
		hover = imgStr + type;
		this.src = hover;
		this.onmouseout = null;
	}

}

//http://javascript-array.com

var timeout	= 50;
var closetimer= 0;
var ddmenuitem= 0;

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

	// close old layer
	if(ddmenuitem) ddmenuitem.style.display = 'none';

	// get new layer and show it
	ddmenuitem = document.getElementById(id);
	ddmenuitem.style.display = 'block';

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

// go close timer
function mclosetime()
{
	closetimer = window.setTimeout(mclose, timeout);
}
function mclosetimedelay() {
    closetimer = window.setTimeout(mclose, '0');
}
// cancel close timer
function mcancelclosetime()
{
	if(closetimer)
	{
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}

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