eGW 1.6rc3 + DB error

Hi

I try to install eGW1.6rc3. When I want install application, a get these error:

SQLSTATE[HY000] [2005] Unknown MySQL server host ':/tmp/mysql50.sock' (3)

In header.inc.php is:

$GLOBALS['egw_domain']['default'] = array(
        'db_host' => ':/tmp/mysql50.sock',
        'db_port' => '',
        'db_name' => 'grup16',
        'db_user' => 'grup16',
        'db_pass' => 'xxx',
        'db_type' => 'mysql',

Please help me. Thank you.

Laco form Slovakia