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

// open hidden layer
function mopen(id)
{	
	// swap pictures
	switch(id) {
		case "m1":
			document.bProd.src='images/hbutton_products.jpg';
			break;
		case "m2":
			document.bReq.src='images/hbutton_request.jpg';
			break;
		case "m3":
			document.bNews.src='images/hbutton_news.jpg';
			break;
		case "m4":
			document.bOpp.src='images/hbutton_opportunity.jpg';
			break;
		case "m5":
			document.bContactUs.src='images/hbutton_contact.jpg';
			break;
	}
	// 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 = 'none';
	document.bProd.src='images/button_products.jpg';
	document.bReq.src='images/button_request.jpg';
	document.bNews.src='images/button_news.jpg';
	document.bOpp.src='images/button_opportunity.jpg';
	document.bContactUs.src='images/button_contact.jpg';
}

// 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;