REM Create mutex:
      SYS "CreateMutex", 0, 0, 0 TO hMutex%

      REM Wait to acquire mutex:
      REPEAT
        SYS "WaitForSingleObject", hMutex%, 1 TO res%
      UNTIL res% = 0

      REM Release mutex:
      SYS "ReleaseMutex", hMutex%

      REM Free mutex:
      SYS "CloseHandle", hMutex%