still nothing happening with my site

here is the configuration

// live (http://www.jobsfixer.com)
$__instances['live'] = array(
    'prefix' => 'jobsfixer.com',
    'db_host' => 'localhost',
    'db_port' => 3306,
    'db_user' => 'user',
    'db_password' => 'pass',
    'db_name' => 'database',
    'db_prefix' => '',
    'app_url' => 'http://www.jobsfixer.com/',
    'ini_error_reporting' => E_ALL,
    'ini_display_errors' => 'on',
    'location' => 'online',
    'environment' => 'prod',
    'rewrite_mode' => 'apache_mod_rewrite'
);

im still  having this problem, i don't see anythng wrong  with this.

Fatal error: Class 'mysqli' not found in /home/jobsfixe/public_html/_includes/class.Db.php on line 16

( help pls