Передача данных по com порту

//---------------------------------------------------------------------------
 
#include <vcl.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
 //HANDLE port;
 DCB dcb;
 port=CreateFileA("COM9", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL );
    if(port==INVALID_HANDLE_VALUE) {
    Memo1->Lines->Add("Не возможно открыть последовательный порт");
 
   }
  // CloseHandle(port);
 
  //далее установим наши параметры
dcb.BaudRate = CBR_19200;
dcb.fBinary = TRUE;
dcb.fOutxCtsFlow = FALSE;
dcb.fOutxDsrFlow = FALSE;
dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
dcb.fDsrSensitivity = FALSE;
dcb.fNull = FALSE;
dcb.fRtsControl = RTS_CONTROL_DISABLE;
dcb.fAbortOnError = FALSE;
dcb.ByteSize = 8;
dcb.Parity = NOPARITY;
dcb.StopBits = 1;
dcb.XonLim=2048;
dcb.XoffLim=512;
dcb.StopBits=ONESTOPBIT;
 
SetCommState(port, &dcb);  //запишем параметры в порт
 
COMMTIMEOUTS CommTimeOuts;
GetCommTimeouts(port, &CommTimeOuts);
CommTimeOuts.ReadIntervalTimeout= 100;
CommTimeOuts.ReadTotalTimeoutMultiplier = 1;
CommTimeOuts.ReadTotalTimeoutConstant = 5;
CommTimeOuts.WriteTotalTimeoutMultiplier = 1;
CommTimeOuts.WriteTotalTimeoutConstant = 100;
SetCommTimeouts(port, &CommTimeOuts);
 
 Memo1->Lines->Add("  Порт COM9 открыт успешно ");
 Memo1->Lines->Add(" скорость 19200");
 
 
 }
 
//---------------------------------------------------------------------------
 
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button2Click(TObject *Sender)
{
 
 CloseHandle(port);
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
 char buffer[1];
 memset(buffer,0,sizeof(buffer));
 buffer[0] |=(1<<0);
 //strcpy(buffer,"SAVE TO COM1");
 DWORD nb;
 OVERLAPPED ov;
 WriteFile(port,buffer,sizeof(buffer),&nb,&ov);
}

//---------------------------------------------------------------------------
 
#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <System.Classes.hpp>
#include <Vcl.Controls.hpp>
#include <Vcl.StdCtrls.hpp>
#include <Vcl.Forms.hpp>
#include <Vcl.ExtCtrls.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:    // IDE-managed Components
    TButton *Button1;
    TMemo *Memo1;
    TButton *Button2;
    TTimer *Timer1;
    void __fastcall Button1Click(TObject *Sender);
    void __fastcall Button2Click(TObject *Sender);
    void __fastcall Timer1Timer(TObject *Sender);
 
 
private:    // User declarations
public:     // User declarations
    __fastcall TForm1(TComponent* Owner);
    HANDLE port;
 
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif

port=CreateFileA("COM9", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL );
// ошибка[bcc32 Error] (432): E2451 Undefined symbol 'port'