Example usage of the $_SERVER['HTTP_USER_AGENT'] variable, use it to detect the ie web browser, for ie specific code such as css gotchas.

<?php
/*
  Example usage of the $_SERVER['HTTP_USER_AGENT'] variable
  use it to detect the ie web browser, for ie specific code
*/

function detect_ie() {
    if (isset($_SERVER['HTTP_USER_AGENT']) && 
    (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== false))
        return true;
    else
        return false;
}

?>