I had ddl which in selected changed it execute some code but when i tried to do that it wasn't worked well WHEN i checked the reason i found that ddl in selected value =0 also i made all well and this is my code

protected void DDlProductFamily_SelectedIndexChanged(object sender, EventArgs e) { if (DDlProductFamily.DataValueField.Contains("ProductCategory_Id")) using (SqlConnection Con = Connection.GetConnection()) { SqlCommand Com = new SqlCommand("GetListViewByProductCategory", Con); Com.CommandType = CommandType.StoredProcedure; Com.Parameters.Add(Parameter.NewInt("@ProductCategory_Id", DDlProductFamily.SelectedValue.ToString())); SqlDataAdapter DA = new SqlDataAdapter(Com); DA.Fill(dt); DataList1.DataSource = dt; DataList1.DataBind(); } }