function grayOut(vis, elementToShow, demoIndex, 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 || 500;
  var opacity = options.opacity || 70;
  var opaque = (opacity / 100);
  var bgcolor = options.bgcolor || '#000000';
  var dark = document.getElementById('darkenScreenObject');
  var popUp = document.getElementById(elementToShow);  
  
  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 
    var pageWidth
	var pageHeight;
	
	if (window.innerHeight && window.scrollMaxY) {// Firefox
		pageHeight = window.innerHeight + window.scrollMaxY + 'px';
		pageWidth = window.innerWidth + window.scrollMaxX + 'px';
		//alert(pageHeight);
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		pageHeight = document.body.scrollHeight + 'px';
		pageWidth = document.body.scrollWidth + 'px';
		//alert(pageHeight);
	} else { // works in Explorer 6 Strict, Mozilla (not FF) and Safari
		pageHeight = "1000px"
		pageWidth = "100%";
		//alert(pageHeight);
		
  	}
	
    //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=0;        
    dark.style.backgroundColor=bgcolor;  
    dark.style.width= pageWidth;
    dark.style.height= pageHeight;
    dark.style.display='block'; 
	
	// show the popup
	popUp.style.display = 'block';
	
	if (demoIndex == 0) {
		// pass the variable to the flash object
		if (isIE) {
			setSwfVariableIE("demo", "stopper", "2");
			//alert('is ie');
		} else {
			setSwfVariableNN("demo", "stopper", "2");						
		}
	}
	
	// fill with data if needed
	if (demoIndex > 0) {
		showDemo(demoIndex);	
	}
  } else {
	if (isIE) {
		//setSwfVariableIE("demo", "stopper", "1");
	} else {
		//setSwfVariableNN("demo", "stopper", "1");						
	}
    dark.style.display='none';
	popUp.style.display = 'none';
	 
  }
}

var isIE = (navigator.appVersion.indexOf("MSIE") != -1);

function setSwfVariableIE(movieName, variableName, value) {
	var swf = document.getElementById(movieName);
	swf.SetVariable(variableName,value);
}

function setSwfVariableNN(movieName, value) {
	if (isIE) {
		var swf = document[movieName];
		swf.SetVariable(variableName,value);
	}
}