The Mark a Display as Invalid routine marks a display as invalid
    and causes the entire display to be redrawn.

    Format

      SMG$INVALIDATE_DISPLAY  display-id

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2  –  Argument

 display-id

    OpenVMS usage:identifier
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Specifies the virtual display affected. The display-id argument
    is the address of an unsigned longword that contains the display
    identifier.

    The display identifier is returned by SMG$CREATE_VIRTUAL_DISPLAY.