>
>sele res
>SET ORDER TO CODE
>GO TOP
>DO WHILE .NOT. EOF()
>IF PERC>=80 .AND. PERC<=100
>	REPL GRADE WITH "A+"
>ENDIF
>IF PERC>=70 .AND. PERC<79.99
>	REPL GRADE WITH "A"
>ENDIF
>.............
>

Update res ;
  SET grade = Icase(;
  PERC>=80 .And. PERC<=100, "A+",;
  PERC>=70 .And. PERC<=80, "A") ;
  WHERE PERC >= 70