function getXMLHTTP()
	{
		var xmlHttp=null;
	    try
		{
			// Firefox, Opera 8.0+, Safari
			 xmlHttp=new XMLHttpRequest();
		}
		catch (e)
		{
			// Internet Explorer
			try
			{
					xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
			}
			catch (e)
			{
					xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			}
		}
		return xmlHttp;
	}

function onload_screen_size()
	{
		xmlHttp=getXMLHTTP()
	    if (xmlHttp==null)
		{
		alert ("Your browser does not support AJAX!");
		return;
	    }
		else
		{
			var screenW = 640, screenH = 480;
			if (parseInt(navigator.appVersion)>3) 
			{
				screenW = screen.width;
				screenH = screen.height;
			}
			else if (navigator.appName == "Netscape" && parseInt(navigator.appVersion)==3 && navigator.javaEnabled()) 
			{
				var jToolkit = java.awt.Toolkit.getDefaultToolkit();
				var jScreenSize = jToolkit.getScreenSize();
				screenW = jScreenSize.width;
				screenH = jScreenSize.height;
			}
			//document.write("Screen width = "+screenW+"<br>"+"Screen height = "+screenH)
		}				
			
			xmlHttp.onreadystatechange=zengo_screen;
			url="ajax-php/screen_size.php?screen_h="+screenH+"&screen_w="+screenW;	
			xmlHttp.open("GET",url,true);
			xmlHttp.send(null);
				
	}

	function zengo_screen()
	{
		if(xmlHttp.readyState==4)
		{		//alert(xmlHttp.responseText);
		
		}
	}