can anyone help me ? I m not able to connect database.

[eluser]the_namdeeW[/eluser]
I would recommend using the built in connection. The whole reason behind using frameworks is to make your life easier.
Just go to /application/config/database.php
This defaults to work with MySQL and just fill in the requirements. Then in your controller just add the following line.
$this->load->database('default');
Good luck!