🚀 go-pugleaf

I've saw specifications for my mobile phone, and there is bunch of AT
commands that response to.
I'm trying to send them to mobile phone like this:

String gszPort;
gszPort = "COM2";
HANDLE hComm;
hComm = CreateFile( gszPort.c_str (),
                    GENERIC_READ | GENERIC_WRITE,
                    0,
                    0,
                    OPEN_EXISTING,
                    FILE_FLAG_OVERLAPPED,
                    0);
if (hComm == INVALID_HANDLE_VALUE) {
        ShowMessage ("Gre�ka: INVALID_HANDLE_VALUE");
        return;
        }
DWORD dwToWrite;
if (WriteABuffer ("AT^SMSO", 10, hComm) == FALSE)
        ShowMessage ("Gre�ka prilikom slanja");

CloseHandle (hComm);

BOOL TForm1::WriteABuffer(char * lpBuf, DWORD dwToWrite, HANDLE hComm)
{
...
   if (!WriteFile(hComm, lpBuf, dwToWrite, &dwWritten, &osWrite)) {
      if (GetLastError() != ERROR_IO_PENDING) {
         fRes = FALSE;
         }
      }

what am i doing wrong ?