procedure _OnError(Sender: PObj; const Error:integer);
   public
...
procedure THITCP_Server._OnError;
begin
  _hi_OnEvent( _event_onError,Error );
end;

constructor THITCP_Server.Create;
begin
   inherited;
   Sock := TSocket.Create;
   Sock.OnConnect := _OnConnect;
   Sock.OnDisconnect := _OnDisConnect;
   Sock.OnRead := _OnRes;
   Sock.OnClientConnect := _OnClientConnect;
   Sock.OnClientDisconnect := _OnClientDisConnect;
   //Sock.OnError := _OnError;
end;