what wrong in the code

iam doing a report named sales
this report read from the item ledger entry table
i want to right a code trlatrd to grouping
because my aim in this report is " if i want the item category code or product group code the report gibe me the total Qty & amount"
step 1 : new report and fill the related fields
step2: open the request page and select grouping
step 3: cal global : grouping as option
groupingvalue as option
valueentryrec as record
the code : If grouping := category then
groupingvalue:= valueentryrec."item category code"
else
groupingvalue:=valueentryrec."product group code"
when i save, an eror ocured