// 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.
		function grayOut(vis, options) {
			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';
			}
		}