Creates a MOP Circuit entity that represents a data link circuit on
    which MOP services are available.  Both the Circuit Name and the
    Circuit Type are required arguments.  An example of a Circuit Name
    is CSMACD-0.  An example of a Circuit Type is CSMA-CD.

    Press the CONTINUE button to create the MOP Circuit entity, or press
    the CANCEL button to cancel this operation.  In either case, you will
    return to the main window.