NVALID_HANDLE_VALUE then

     MessageBox(0,''Error opening com port!'',''Notice'',MB_OK);

  SetupComm(hNewCommFile,1024,1024); // 设置缓冲区大小及主要通讯参数

  GetCommState( hNewCommFile,dcb);

  dcb.BaudRate :=9600;

  dcb.ByteSize :=8;

  dcb.Parity :=NOPARITY;

  dcb.StopBits := ONESTOPBIT;

  Error := SetCommState( hNewCommFile, dcb );

  if ( not Error) then MessageBox(0,''SetCommState Error!'',''Notice'',MB_OK);

  dwWhereToStartWriting := 0;

  dwNumberOfBytesWritten := 0;

  dwNumberOfBytesToWrite :=RichEdit1.GetTextLen;

  if (dwNumberOfBytesToWrite=0) then

    begin

      ShowMessage(''Text Buffer is Empty!'');

      Exit;

    end

  else

    begin

      pDataToWrite:=StrAlloc(dwNumberOfBytesToWrite+1);

      try

        RichEdit1.GetTextBuf(pDataToWrite,dwNumberOfBytesToWrite);

        Label1.Font.Color :=clRed;

        FillChar(Write_Os,SizeOf(write_os),0);

        // 为重叠写创建事件对象

        Write_Os.hEvent := CreateEvent(nil,True,False,nil);

        SetCommMask(hNewCommFile,EV_TXEMPTY);

        Label1.Caption:=''正在发送数据!'';

        repeat

           Label1.Repaint;

           // 发送通讯数据

           if not WriteFile( hNewCommFile,pDataToWrite[dwWhereToStartWriting],

                              dwNumberOfBytesToWrite,dwNumberOfBytesWritten,

                         @write_os ) then

           begin

               ErrorFlag :=GetLastError;

               if ErrorFlag<>0 then

                 begin

                  if ErrorFlag=ERROR_IO_PENDING then

           &nb