Install GPG/PGP on Ubuntu 12.04

Hi,

I need assistance to load GPG/PGP libraries on Ubuntu server 12.04.

I have installed all required libraries on this server.
- gnupg
- libgpg-error
- gpgme
I checked in phpinfo and got the result for gnupg. but I am quit confusing about, are these libraries are loaded properly or not?. when I execute the
below code :
<?php
$gnupg = new gnupg();
print_r($gnupg);
 or
$res = gnupg_init();
?>
this code gives me fatal error for class not found.

Could you please assist me on this?

Where we need to check :
in whcih folder?
in which library.
in how to test this.
Please provide step-by-step on this this will very help full to us.

Thanks,
Swapnil