$client=$app->db->queryOneRecord("SELECT default_dnsserver FROM sys_group, client WHERE sys_group.client_id = client.client_id and sys_group.groupid = $client_group_id");
$sql="SELECT server_id,server_name FROM server WHERE server_id = ".$client['default_dnsserver'];
}else{
$sql="SELECT server_id,server_name FROM server WHERE dns_server = 1 ORDER BY server_name";