/*sfHover = function() {
	var sfEls = document.getElementById("nav").getElementsByTagName("LI");
	for (var i=0; i<sfEls.length; i++) 
	    {
		    sfEls[i].onmouseover=function() {
			    this.className+=" sfhover";
		    }
		    sfEls[i].onmouseout=function() 
		    { 
		        this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
		    }
	    }
    }
if (window.attachEvent) window.attachEvent("onload", sfHover);
*/
function roll(img_name, img_src)
   {
   document[img_name].src = img_src;
   }

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

// 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;