UPDATE

        LAS\UPDATE

    Update the LAST version of the observation in the R buffer in the output
    file.  You  can  update only the last version. The update OVERWRITES the
    observation. This command MUST BE USED WITH CAUTION; in case of  complex
    manipulations  of  observations, you may get confused and erase precious
    data.

    If more space is needed (e.g., the new version has more header  informa-
    tion),  an  error  is  returned.  You MUST then WRITE the observation to
    avoid loss of information.

    The only typical case where it may be used is in the following sequence:
        GET Number
        MINIMIZE or MODIFY
        UPDATE