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 || 99998;
	  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.style.width='100%';
	        tnode.style.height='100%';
	        tnode.style.position = 'fixed';
	        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) {
		 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';
	 }
}