void __fastcall TfrmClient::mnuFileClick(TObject *Sender)
{
    TUpThread *UpThread;

    TCPFile->Host = txtIP->Text;
    TCPFile->Port = StrToInt(txtPort->Text);
    TCPFile->Connect();
    if( TCPFile->Connected() )
    {
        if( dlgOpen->Execute() ) FlgOpen = True;
        else FlgOpen = False;
        if( FlgOpen ) UpThread = new TUpThread( false );
        else    TCPFile->Disconnect();
    }
    else
        Application->MessageBoxA("서버가 동작하지 않습니다", "경고", MB_OK );
}

클래스 구현부분..

class TUpThread : public TThread
{
    protected:
        void __fastcall Execute()
        {
           TFileStream *FStream;

           FreeOnTerminate = True;
           FStream = new TFileStream( ExtractFileName( frmClient->dlgOpen->FileName), fmOpenRead );
           frmClient->TCPFile->WriteLn('5' & ExtractFileName( frmClient->dlgOpen->FileName) );
           Sleep(200);
           frmClient->TCPFile->WriteStream( FStream );
           FStream->Free();
           frmClient->TCPFile->Disconnect();
        }

    public:
  __fastcall TUpThread(bool CreateSuspended);
};

[Linker Error] Unresolved external 'TupThread::' referenced from E:\indy\클라이언트\Client.Obj
[Linker Error] Unresolved external '__fastcallTUpThread::TUpThread(bool)' referenced from E:\indy\클라이언트\Client.Obj

고수님들 도와주세요...