protected override void OnNavigatedTo(NavigationEventArgs e) { if (comboList.SelectedItem == null) { linkQuit.Visibility = Windows.UI.Xaml.Visibility.Collapsed; lblSelectedGrade.Text = "No Grade Selected"; } insert = new InsertModule(); if (model.getEnglish() == null) { insert.populateEnglishTables(); } if (model.getMaths() == null) { insert.pupulateMathsTable(); } if (model.getBusiness() == null) { insert.pupulateBusinessTable(); } if (model.getAccounting() == null) { insert.pupulateAccountingTable(); } if (model.getPhysics() == null) { insert.pupulatePhysicsTable(); } comboList.Items.Add("GRADE 1"); comboList.Items.Add("GRADE 2"); comboList.Items.Add("GRADE 3"); comboList.Items.Add("GRADE 4"); comboList.Items.Add("GRADE 5"); comboList.Items.Add("GRADE 6"); comboList.Items.Add("GRADE 7"); comboList.Items.Add("GRADE 8"); comboList.Items.Add("GRADE 9"); comboList.Items.Add("GRADE 10"); comboList.Items.Add("GRADE 11"); comboList.Items.Add("GRADE 12"); base.OnNavigatedFrom(e); }