>>
>>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