🚀 go-pugleaf

Hello There
I am trying to prevent several instances of my program running. I am using C++ Builder v5 and OS is XP. My main looks like below:

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WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
  HANDLE mutex;

  try
  {
    const char mutexname[]="program";
    mutex=OpenMutex(0,false,mutexname);

    //If mutex does not exist = program is not running
    if (mutex==NULL)
    {
      mutex=CreateMutex(NULL, true,mutexname);
    }
    //mutex exists = program is aleady running
    else
    {
      ShowMessage("Program is already running");
      return 0;
    }

    Application->Initialize();
    Application->Title = "program";
    Application->CreateForm(__classid(TForm1), &Form1);
    Application->Run();
  }
  catch (Exception &exception)
  {
     Application->ShowException(&exception);
  }
  ReleaseMutex(mutex);
  return 0;
}
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