Encrypt Querystring in php?

[Mit Chauhan]

JAI MATADI all ..

i have two web pages called as
1) "page1.php"
2)"result page.php"

and in "result page.php" in addressbar i want to encrypt the querystring .. here my code ..

------------------------------------
page1.php
----------------
<?php
$u = "mit";
echo "<a href='result page.php?user=$u'>User</a>";

?>
------------------------------------

------------------------------------
result page.php
----------------
<?php

$user = $_REQUEST["user"];
echo $user;



?>
------------------------------------
m able to see the "user=mit" in my addressbar .. but i want to encrypt my USERNAME .. how can i do this ..

php experts .. your any help would be highly appreciated by me ..

thanks . .