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 || 70;
	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';
	}
}