The Erase Line routine erases all or part of a line in a virtual
    display.

    Format

      SMG$ERASE_LINE  display-id [,start-row] [,start-column]

1  –  Returns

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

2  –  Arguments

 display-id

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

    Specifies the virtual display to be 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.

 start-row

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the line at which the erase operation starts. The
    start-row argument is the address of a signed longword that
    contains the number of the row at which the erasure starts. If
    omitted, start-column is also ignored and the current cursor
    position is used.

 start-column

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the column at which the erase operation starts. The
    start-column argument is the address of a signed longword that
    contains the number of the column at which the erasure starts.
    If omitted, start-row is also ignored and the current cursor
    position is used.