<script language='JavaScript'>
<!--
function detect()
{
alert('Screen resolution is '+screen.width+'x'+screen.height+'.');
}
//-->
</script>

<a href='#' onclick='detect();return false;'>Detect Screen Resolution</a>

<?php

if(!isset($_GET['screen_check']))
{
	/* This code will be executed if screen resolution has not been detected.*/
	echo "<script language='JavaScript'>
	<!-- 
	document.location=\"$PHP_SELF?screen_check=done&Width=\"+screen.width+\"&Height=\"+screen.height;
	//-->
	</script>";
}
else 
{    
	/* This code will be executed after screen resolution is detected.*/
    if(isset($_GET['Width']) && isset($_GET['Height'])) {
		// Resolution  detected
		echo "<h1>Your screen resolution is ".$_GET['Width']." x ".$_GET['Height'].".</h1><br />";
			//Display page as per resolution
			if(($_GET['Width']>1024)&&($_GET['Height']>768)) {
				echo "<b>This will be displayed when screen resolution is greater than 1024x768.</b>";
			}
			else {
				//Display page as per resolution
				echo "<b>This will be displayed when screen resolution is either equal to or less than 1024x768.</b>";
			}
     }
     else {
               // Resolution not detected
     }
}
?>