protected void buildingDropDownList_SelectedIndexChanged(object sender, EventArgs e) { try { List <Room> rooms = new List <Room>(); aScheduleManager = new ScheduleManager(); rooms = aScheduleManager.GetAllRooms(Convert.ToInt16(buildingDropDownList.Text)); roomDropDownList.DataSource = rooms; roomDropDownList.DataBind(); } catch (SqlException sqlException) { msgLabel.ForeColor = Color.Red; msgLabel.Text = "Database error.See details error: " + sqlException.Message; } catch (Exception exception) { msgLabel.ForeColor = Color.Red; string errorMessage = "Unknow error occured."; errorMessage += exception.Message; if (exception.InnerException != null) { errorMessage += exception.InnerException.Message; } msgLabel.Text = errorMessage; } }