Hi Saquib :)
You code looks very good, but I hope you will consider making the password encryption function more secure in future.
I don't think using Base64 and string reverse is strong enough to protect passwords, especially if someone that doesn't know anything about security decided to use this script on a live site.
A basic MD5 or sha1 hash combined with a SALT would offer much stronger protection.
You can find lots of good examples here:
php.net/manual/en/function.md5.php
php.net/manual/en/function.sha1.php
php.net/manual/en/function.hash.php
Keep up the good work.