private void AddUser_Click(object sender, RoutedEventArgs e) { bool isDigitsOnly = true; foreach (char c in AddedUsername.Text) { if (!(c < '0' || c > '9')) { isDigitsOnly = false; } } if (isDigitsOnly) { UserAddedText.Text = "Error! Please enter number ID of user!"; } else if (GlobalVariables.userInGroup(GlobalVariables.emailToID(AddedUsername.Text), GlobalVariables.selectedGroup)) { UserAddedText.Text = "Error! User already in group!"; } else if (GlobalVariables.userInDatabase(Convert.ToInt32(AddedUsername.Text))) { UserAddedText.Text = AddedUsername.Text + " Added!"; GlobalVariables.insertPersonIntoGroup(Convert.ToInt32(AddedUsername.Text), GlobalVariables.selectedGroup); } else { UserAddedText.Text = AddedUsername.Text + " is not in database."; } AddedUsername.Text = ""; UserAddedText.Visibility = Visibility.Visible; }