stringsql="select distinct SheetName,AccountingUnit,Department,UnitType from per_sheet st join im_data dt on st.ID = dt.SheetID where st.AllotID = @allotId";
stringsql="select distinct SheetName,AccountingUnit,Department,UnitType from per_sheet st join im_data dt on st.ID = dt.SheetID where st.AllotID = @allotId and ifnull(AccountingUnit, '') != '' ";