function showOverlay(){
	var overlay = $('overlay');
	overlay.style.backgroundColor = 'black';
	overlay.style.position = 'absolute';
	overlay.style.top = 0;
	overlay.style.left = 0;
	if (navigator.userAgent.toLowerCase().indexOf("msie") ==-1) {
		overlay.style.height = '100%';
	} else {
		overlay.style.height = screen.height;
	}
	overlay.style.width = $('wrapper').getWidth() + 'px';
	overlay.style.zIndex = 15000;
	overlay.setOpacity(0.7);
	overlay.style.display = 'block';
}

function hideOverlay(){
	var overlay = $('overlay');
	overlay.style.display = 'none';
}

function closeBrowserUpgradePopup(){
	hideOverlay();
	$('browser_upgrade_popup').style.display = 'none';
}

function showBrowserUpgradePopup(){
	var getInfo = new Ajax.Request(
	'/remote.php?module=browser_upgrade', 
	{
		method: 'get', 
		onSuccess: function(requestResponse) {
			showOverlay();
			$('browser_upgrade_popup').innerHTML = requestResponse.responseText;
			$('browser_upgrade_popup').style.left = (($('wrapper').getWidth() - 500)/2) + 'px';
			$('browser_upgrade_popup').style.display = 'block';
		}
	});
}