Hello guys,
I developed a website in OpenCart locally. Now, i have uploaded it to my web-hosting server. The front end of the e-shop loads properly but when i try to load backoffice or admin area, i am getting Error: Could not load database file mysql!

my code is:
Code:
// DB
define('DB_DRIVER','mysql');
define('DB_HOSTNAME','localhost');
define('DB_USERNAME','kla_user');
define('DB_PASSWORD','*****');
define('DB_DATABASE','kla_db');
define('DB_PREFIX','kla_')
What could be the possible reason? i asked some friend and he told me that this sort of errors are basically driver errors...have your say and please help me to solve this.