function addOnloadEvent(onloadFnc)
{	
	if ( typeof window.addEventListener != "undefined" )
	{
		window.addEventListener( "load", onloadFnc, false );
	}
	else if ( typeof window.attachEvent != "undefined" ) 
	{
		window.attachEvent( "onload", onloadFnc );
	}
	else 
	{
		if ( window.onload != null ) 
		{
			var oldOnload = window.onload;
			window.onload = function ( e ) {
				oldOnload( e );
				window[onloadFnc]();
				};
		}
		else
		{
			window.onload = onloadFnc;
		}
	}
}


function grayOut(vis, containerId, options) 
{
	/// <summary>
	/// Pass true to gray out screen, false to ungray options are optional.  This is a JSON object with the following (optional) properties  
	/// </summary>
	/// <param name="vis" type="bool">
	/// True for gray, false for hide gray
	/// </param>
	/// <param name="options">
	/// 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. 
	/// </param>
	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'); 
	
	var container = document.getElementById(containerId);
	var useCustomContainer = container != null;
	
	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;
		
		if ( useCustomContainer )
			tbody = container.parentNode;
		else
			tbody = document.getElementsByTagName("body")[0];
		

		var tnode = document.createElement('div');			// Create the layer.        
		
		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 ( useCustomContainer )
	{
		dark.style.position='relative';						// Position relative
		var browserName = getBrowser();
		
		if ( browserName == "IE" )
			dark.style.top='-' + container.offsetHeight + 'px';	
		
		dark.style.left='0px';								// Left corner of the page       
	}
	else
	{
		dark.style.position='absolute';				// Position absolute
		dark.style.top='0px';						// In the top        
		dark.style.left='0px';						// Left corner of the page       
	}
	
	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;      
		
		if ( useCustomContainer )
		{
			dark.style.width = container.offsetWidth+'px';    
			dark.style.height = container.offsetHeight+'px';  
		}
		else
		{
			dark.style.width = pageWidth;    
			dark.style.height = pageHeight;    
		}
		
		dark.style.display='block';                            
	} 
	else 
	{     
		dark.style.display='none';  
	}
}

function getBrowser()
{
	//detect browser type
    if (navigator.appName == 'Microsoft Internet Explorer')
		return "IE";
        
	if (navigator.appName == 'Netscape')
		return "NETSCAPE";
	
    agent = navigator.userAgent;
	if ( (agent.toLowerCase().indexOf('opera 7')>-1) || (agent.toLowerCase().indexOf('opera/7')>-1) )
		return "OPERA";
		
    if ( (agent.toLowerCase().indexOf('opera 9')>-1) || (agent.toLowerCase().indexOf('opera/9')>-1) )
		return "OPERA9";

}