HANDLE hFile =
       CreateFile
         (
         "abc.txt", //  name of the file
         GENERIC_READ | GENERIC_WRITE,	// access (read-write) mode
         0, // share mode
        NULL, // pointer to security attributes
         OPEN_ALWAYS,	// how to create
         FILE_ATTRIBUTE_NORMAL,	// file attributes
         NULL 	// handle to file with attributes to copy
         );
 
    if (hFile != INVALID_HANDLE_VALUE)
    {
       Button1->Caption = "Open";
       HANDLE hMap =
       CreateFileMapping
         (hFile, // handle to file to map
          NULL,	// optional security attributes
          PAGE_READWRITE,	// protection for mapping object
          0,	// high-order 32 bits of object size
          1024,	// low-order 32 bits of object size
          NULL // name of file-mapping object
          );
 
       if (hMap != NULL)
       {
         Button1->Caption = "Mapped";
         void * p = MapViewOfFile
           (hMap, // file-mapping object to map into address space
            FILE_MAP_WRITE,	// access mode
            0,	// high-order 32 bits of file offset
            0,	// low-order 32 bits of file offset
            512	// number of bytes to map
            );
 
         if (p != NULL)
         {
            Button1->Caption = "View Mapped";
            char * c = (char *) p;
            c[0] = 'A';
            c[1] = 'B';
            c[2] = 'C';
            c[3] = 0;
            UnmapViewOfFile (hMap);
         }
         CloseHandle (hMap);
       }
       else
       {
         Button1->Caption = "Error";
       }
    CloseHandle (hFile);
    }