請問下面配置有慎麼問題?

Question

if((hComDev=CreateFile("COM1",GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL))==INVALID_HANDLE_VALUE) 
{ MessageBox("Com1 can't connect!");
WriteFile(
// return;
}
else 
flag=1;
}
COMMTIMEOUTS timeouts; 
SetCommTimeouts(hComDev,&timeouts);
SetupComm(hComDev,1024,512);
GetCommState(hComDev,&dcb);
dcb.BaudRate=38400;
dcb.fParity=EVENPARITY;
dcb.ByteSize=7;
dcb.StopBits=ONESTOPBIT;
//dcb.fDtrControl = DTR_CONTROL_ENABLE;
ClearCommError(hComDev,NULL,NULL);
//EscapeCommFunction(hComDev,TRUE);
SetCommState(hComDev,&dcb);
連接後寫給設備,設備不能反映,
但是如果用超級終端連接後,就ok了.
請問位慎麼