//Escape button handler ::: go back to homepage
 private void HandleEsc(object sender, KeyEventArgs e)
 {
     if (e.Key == Key.Escape)
     {
         homepage homepage = new homepage();
         MainFrame.NavigationService.Navigate(homepage);
     }
 }
        public MainWindow()
        {
            InitializeComponent();
            this.PreviewKeyDown += new KeyEventHandler(HandleEsc);

            WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen;

            homepage homepage = new homepage();

            MainFrame.NavigationService.Navigate(homepage);
        }
        //Click on home icon
        private void btn_home_Click(object sender, RoutedEventArgs e)
        {
            homepage homepage = new homepage();

            MainFrame.NavigationService.Navigate(homepage);
        }