Database driver unexpected error

I have installed connction manually. In my settings.php,

$databases = array (
'default' =>
array (
'default' =>
array (
'database' => 'drupal',
'username' => 'root',
'password' => '',
'host' => 'localhost',
'port' => '',
'driver' => 'mysql',
'prefix' => '',
),
),
);
I receive following error when trying to access my site,

The website encountered an unexpected error. Please try again later.

Notice: Undefined offset: 0 in Database::parseConnectionInfo() (line 1529 of C:\xampp\htdocs\cls\includes\database\database.inc).
Notice: Undefined index: driver in Database::openConnection() (line 1681 of C:\xampp\htdocs\cls\includes\database\database.inc).
Notice: Undefined index: driver in Database::openConnection() (line 1681 of C:\xampp\htdocs\cls\includes\database\database.inc).
Notice: Undefined index: driver in Database::openConnection() (line 1681 of C:\xampp\htdocs\cls\includes\database\database.inc).
DatabaseDriverNotSpecifiedException: Driver not specified for this database connection: default in Database::openConnection() (line 1682 of C:\xampp\htdocs\cls\includes\database\database.inc).
Notice: Undefined index: driver in Database::openConnection() (line 1681 of C:\xampp\htdocs\cls\includes\database\database.inc).