In the ABAP code, make sure you check which field-key these checks refer to, otherwise you may find the checks also work for other field-keys too..
So the code could be:
* perform the ususal order type, plant, SY-BATCH/SY-BINPT, authorisation checks as required
IF AFVGD_IMP-SLWID = '00000001'.
IF AFVGD_IMP-USR00 is not initial and AFVGD_IMP-USR00 > 1500
MESSAG E123(00).
ENDIF.
ENDIF.
PeteA