Why does setcookie function not work?

<?php // RAY_cookie_example.php
 
// RECEIVE FORM INPUT AND SET A COOKIE WITH THE NAME AND VALUES FROM THE FORM
// MAN PAGE: http://us.php.net/manual/en/function.setcookie.php
// TO SEE COOKIES IN FIREFOX, FOLLOW TOOLS => OPTIONS => PRIVACY => SHOW COOKIES
 
define('COOKIE_LIFE', 60*60*24); // A 24-HOUR DAY IN SECONDS ( = 86,400 )
 
if (!empty($_POST)) // IF THE FORM HAS BEEN POSTED
{
 
// TIDY UP THE POST INPUT
   $name = substr(clean_string($_POST["name"]),0,16);
   $data = substr(clean_string($_POST["data"]),0,16);
 
// BE SURE WE HAVE USEFUL INFORMATION
   if ( ($name == '') || ($data == '') ) die("MISSING INPUT: PLEASE <a href=\"$PHP_SELF\">TRY AGAIN</a>");
 
// CONSTRUCT THE COOKIE
// USE THIS TO MAKE COOKIE EXPIRE AT END OF SESSION
   $cookie_expires	= 0;
 
// USE THIS TO MAKE A PERSISTENT COOKIE - DEFINE COOKIE_LIFE IN SECONDS - date('Z') IS UTC OFFSET IN SECONDS
   $cookie_expires	= time() + date('Z') + COOKIE_LIFE;
 
// CHOOSE THE COOKIE NAME AND VALUE
   $cookie_name 	= $name;
   $cookie_value	= $data;
 
// MAKE THE COOKIE AVAILABLE TO ALL DIRECTORY PATHS IN THE WWW ROOT
   $cookie_path	= '/';
 
// MAKE THE COOKIE AVAILABLE TO ALL SUBDOMAINS - DOMAIN SETTING STARTS WITH DOT - NO WWW, ETC.
   $cookie_domain	= ereg_replace('^www', '', strtolower($_SERVER["HTTP_HOST"]));
 
// MAKE THE COOKIE AVAILABLE TO HTTP, NOT JUST HTTPS
   $cookie_secure	= FALSE;
 
// HIDE COOKIE FROM JAVASCRIPT
   $cookie_http	= TRUE;
 
// SET THE COOKIE
   if (setcookie($cookie_name, $cookie_value, $cookie_expires, $cookie_path, $cookie_domain, $cookie_secure, $cookie_http))
   {
      echo "<br/>SUCCESS!  THE COOKIE HAS BEEN SET AND WILL BE AVAILABLE TO THE NEXT PAGE LOAD \n";
   } else {
      echo "<br/>FAILURE!  THE COOKIE WAS NOT SET AS EXPECTED \n";
   }
 
// AT THIS POINT, THE COOKIE HAS BEEN SET, BUT IT IS _NOT_ AVAILABLE TO THIS SCRIPT.  IT WILL BE AVAILABLE TO THE NEXT SCRIPT!
   echo '<pre>$_COOKIE CONTAINS '; var_dump($_COOKIE); echo "</pre>\n";
   echo '<pre>$_POST CONTAINS ';   var_dump($_POST);   echo "</pre>\n";
   echo "<br/>THE COOKIE HAS BEEN SET WITH THESE VALUES: \n";
   echo "<br/>COOKIE NAME: $cookie_name \n";
   echo "<br/>COOKIE VALUE: $cookie_value \n";
   echo "<br/>COOKIE EXPIRES: $cookie_expires ";
   echo " == " . date('r') . "\n";
   echo "<br/>COOKIE PATH: $cookie_path \n";
   echo "<br/>COOKIE DOMAIN: $cookie_domain \n";
   echo "<br/>COOKIE SECURE: "; var_dump($cookie_secure); echo " \n";
   echo "<br/>COOKIE HTTP: ";   var_dump($cookie_http);   echo " \n";
 
   echo "<br/>";
   echo "<br/>TO SEE THE COOKIES, IF ANY, <a href=\"$PHP_SELF\">CLICK HERE</a> \n";
   echo "<br/>";
}
 
// END OF SETTING THE COOKIE
?>
 
 
<form method="post">
COOKIE NAME: <input name="name" /><br/>
COOKIE DATA: <input name="data" /><br/>
<input type="submit" />
</form>
 
 
<?php
// SHOW THE COOKIE ARRAY, IF ANY
echo '<pre>$_COOKIE CONTAINS '; var_dump($_COOKIE); echo "</pre>\n";
 
 
// A FUNCTION TO FORCE A STRING TO CHARACTERS ONLY
function clean_string($string)
{
   return trim(ereg_replace('[^a-zA-Z0-9_]', '', $string));
}
?>

                                              

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