populate select options from extra mysql table data

You should not use mysql_fetch_array()

Use wordpress built-in functions, like this:

$SQL = "SELECT * FROM pt_country ORDER BY name";
$rows = $wpdb->get_results( $SQL );
foreach($rows as $r){
 print_r($r);
}

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)