browsertest.php

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
    <title>Your Browser</title>
</head>
<body>
<h1>Hello</h1>
<p>
<?php
// Internet Explorer versions up to 10 include MSIE in the user agent string.
// Version 11 no longer includes it unless Compatibility View is turned on.
    if( strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== FALSE ) { // not equal value or not equal type
      print "You are using Internet Explorer version 10 or earlier (or you have enabled Compatibility View).\n";
    }
    else {
      print "You are not using Internet Explorer version 10 or earlier.\n";
    }
?>
</p>
</body>
</html>