private void Login_btn_Click(object sender, RoutedEventArgs e) { //if its login page validate the username and password if (signup_btn1.Content.Equals("Login")) { string UserNam = Properties.Settings.Default.UserName; string Password = Properties.Settings.Default.Password; string u_name = UserName.Text; string password = pass.Password; //show the phonebook page if valid details if (UserNam.Equals(u_name) && Password.Equals(password)) { PhoneBook pb = new PhoneBook(); pb.Show(); this.Hide(); } else { //throw error if invalid details MessageBox.Show("Please Enter valid username and password", "Wrong Password", MessageBoxButton.OK, MessageBoxImage.Error); } } //if its signup page set the setting of app to save the details of signup information else { string u_name = UserName.Text; string password = pass.Password; //if the passwords match save the details if (password.Equals(rpass.Password)) { Properties.Settings.Default.UserName = u_name; Properties.Settings.Default.Password = password; Properties.Settings.Default.Save(); this.Hide(); MainWindow mw = new MainWindow(); mw.Show(); } else { //if password do not match in two fields throw error MessageBox.Show("Password MisMatch ", "Password Error", MessageBoxButton.OK, MessageBoxImage.Error); } } }