The Delete Characters routine deletes characters in a virtual
    display.

    Format

      SMG$DELETE_CHARS  display-id ,number-of-characters ,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

    Identifies the virtual display from which characters are to be
    deleted. 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.

 number-of-characters

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

    Specifies the number of characters to be deleted. The number-
    of-characters argument is the address of a signed longword that
    contains the number of characters to be deleted.

 start-row

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

    Specifies the row position at which to start the deletion. The
    start-row argument is the address of a signed longword that
    contains the row number at which to start the deletion.

 start-column

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

    Specifies the column position at which to start the deletion. The
    start-column argument is the address of a signed longword that
    contains the column position at which to start the deletion.