Specified cast is not valid.

Hi Guys,

I am just trying to update on a grid

but i keep geting the above error

can't really figure this out!!

full code
public void dgCompensation_Update(Object Sender, DataGridCommandEventArgs e)
            {
   
                  string employerId = e.Item.Cells[1].Text;
                  //string  destinationelements = ((TextBox)e.Item.Cells[2].Controls[0]).Text;
//                  int deduction = Int32.Parse(((DropDownList)e.Item.Cells[2].Controls[1]).SelectedItem.Value);

                  string deduction = ((DropDownList)e.Item.Cells[2].Controls[1]).SelectedItem.Value;========highlighted
      
                  SqlConnection objConnection = new SqlConnection("Server=(10.217.1.85);Database=ADC11;Password=;Persist Security Info=True;User ID=sa;");
                  SqlCommand updateCommand = new SqlCommand();

                  updateCommand.Connection = objConnection;
                  updateCommand.CommandText = "update DestinationElements set DestinationElement = @DestinationElements, Deduction = @Deduction where EmployerId = @EmployerId";
                  updateCommand.Parameters.Add("@EmployerId", SqlDbType.NVarChar, 20).Value = employerId;
                  //updateCommand.Parameters.Add("@DestinationElements", SqlDbType.NChar, 50).Value = destinationelements;
                  updateCommand.Parameters.Add("@Deduction", SqlDbType.Int).Value = deduction;
               
                  try
                  {
                        objConnection.Open();
                        updateCommand.ExecuteNonQuery();
                      }
   
                  catch (SqlException SqlEx)
                  {
                        lblStatus.Text = SqlEx.Message.ToString();
                  }
   
                  catch (Exception ex)
                  {
                        lblStatus.Text = ex.Message.ToString();
                  }
   
                  finally
                  {
                        objConnection.Close();
                  }
   
                  dgCompensation.EditItemIndex = -1;
                  BindGrid();
   
            }