function grayOut(vis, options) {
	// Pass true to gray out screen, false to ungray
	// options are optional.  This is a JSON object with the following (optional) properties
	// opacity:0-100         // Lower number = less grayout higher = more of a blackout 
	// zindex: #             // HTML elements with a higher zindex appear on top of the gray out
	// bgcolor: (#xxxxxx)    // Standard RGB Hex color code
	// grayOut(true, {'zindex':'50', 'bgcolor':'#0000FF', 'opacity':'70'});
	// Because options is JSON opacity/zindex/bgcolor are all optional and can appear
	// in any order.  Pass only the properties you need to set.
	var options = options || {}; 
	var zindex = options.zindex || 50;
	var opacity = options.opacity || 60;
	var opaque = (opacity / 100);
	var bgcolor = options.bgcolor || '#000000';
	var dark=document.getElementById('darkenScreenObject');
	if (!dark) {
		// The dark layer doesn't exist, it's never been created.  So we'll
		// create it here and apply some basic styles.
		// If you are getting errors in IE see: http://support.microsoft.com/default.aspx/kb/927917
		var tbody = document.getElementsByTagName("body")[0];
		var tnode = document.createElement('div');           // Create the layer.
			tnode.style.position='absolute';                 // Position absolutely
			tnode.style.top='0px';                           // In the top
			tnode.style.left='0px';                          // Left corner of the page
			tnode.style.overflow='hidden';                   // Try to avoid making scroll bars            
			tnode.style.display='none';                      // Start out Hidden
			tnode.id='darkenScreenObject';                   // Name it so we can find it later
		tbody.appendChild(tnode);                            // Add it to the web page
		dark=document.getElementById('darkenScreenObject');  // Get the object.
	}

	if (vis) {
		// Calculate the page width and height 
		if (document.body && (document.body.scrollWidth || document.body.scrollHeight))
		{
			var pageWidth = document.body.scrollWidth+'px';
			var pageHeight = document.body.scrollHeight+'px';
		}
		else if (document.body.offsetWidth)
		{
			var pageWidth = document.body.offsetWidth+'px';
			var pageHeight = document.body.offsetHeight+'px';
		}
		else
		{
			var pageWidth='100%';
			var pageHeight='100%';
		}   
		//set the shader to cover the entire page and make it visible.
		dark.style.opacity=opaque;                      
		dark.style.MozOpacity=opaque;                   
		dark.style.filter='alpha(opacity='+opacity+')'; 
		dark.style.zIndex=zindex;        
		dark.style.backgroundColor=bgcolor;  
		dark.style.width= pageWidth;
		dark.style.height= pageHeight;
		dark.style.display='block';                          
	}
	else
	{
		dark.style.display='none';
	}
}

function ShowPanel(vis, filename)
{
	var panel = document.getElementById('popupFrame');
	if (vis)
	{
		panel.src = filename + '.php';
		panel.style.display = 'block';
	}
	else
	{
		panel.style.display = 'none';
		panel.src = 'blank.html';
	}
}

// constants to define the title of the alert and button text.
var ALERT_TITLE = "Balado.tv";
var ALERT_BUTTON_TEXT = "Close | Fermer";

// over-ride the alert method only if this a newer browser.
// Older browser will see standard alerts
if(document.getElementById) {
	window.alert = function(txt) {
		createCustomAlert(txt);
	}
}

function createCustomAlert(txt) {
	// shortcut reference to the document object
	d = document;

	// if the modalContainer object already exists in the DOM, bail out.
	if(d.getElementById("modalContainer")) return;

	// create the modalContainer div as a child of the BODY element
	mObj = d.getElementsByTagName("body")[0].appendChild(d.createElement("div"));
	mObj.id = "modalContainer";
	 // make sure its as tall as it needs to be to overlay all the content on the page
	mObj.style.height = document.documentElement.scrollHeight + "px";

	// create the DIV that will be the alert
	alertObj = mObj.appendChild(d.createElement("div"));
	alertObj.id = "alertBox";
	// MSIE doesnt treat position:fixed correctly, so this compensates for positioning the alert
	if(d.all && !window.opera) alertObj.style.top = document.documentElement.scrollTop + "px";
	// center the alert box
	alertObj.style.left = (d.documentElement.scrollWidth - alertObj.offsetWidth)/2 + "px";

	// create an H1 element as the title bar
	h1 = alertObj.appendChild(d.createElement("h1"));
	h1.appendChild(d.createTextNode(ALERT_TITLE));

	// create a paragraph element to contain the txt argument
	msg = alertObj.appendChild(d.createElement("p"));
	msg.innerHTML = txt;

	// create an anchor element to use as the confirmation button.
	btn = alertObj.appendChild(d.createElement("a"));
	btn.id = "closeBtn";
	btn.appendChild(d.createTextNode(ALERT_BUTTON_TEXT));
	btn.href = "#";
	// set up the onclick event to remove the alert when the anchor is clicked
	btn.onclick = function() { removeCustomAlert();return false; }
}

// removes the custom alert from the DOM
function removeCustomAlert() {
	document.getElementsByTagName("body")[0].removeChild(document.getElementById("modalContainer"));
}