errorr

 if (Btnsave.Text == "SAVE")
            {

                DivisionInfo infodivision = new DivisionInfo();
                infodivision.classId = decimal.Parse(DropDownList1.SelectedValue.ToString()); --------input string not in currect format
                infodivision.divisionName = TxtdivisionName.Text;
                DivisionSp spdivision = new DivisionSp();
                spdivision.divisionAdd(infodivision);
                gridfill();
                clear();
            }
            else
            {

                DivisionInfo infodivision = new DivisionInfo();
                infodivision.classId = decimal.Parse(ViewState["divisionId"].ToString());----------------input string not in currect format
                infodivision.divisionName = TxtdivisionName.Text;
                DivisionSp spdivision = new DivisionSp();
                infodivision.divisionId = decdivisionId;
                spdivision.divisionEdit(infodivision);
                Btnsave.Text = "SAVE";
                gridfill();
                clear();
            }
i check out selected item the n also same eerror