async void OnItemSelected (object sender, SelectedItemChangedEventArgs e)
		{
			if (listView.SelectedItem != null) {
				var detailPage = new DetailPage ();
				detailPage.BindingContext = e.SelectedItem as Contact;
				listView.SelectedItem = null;
				await Navigation.PushModalAsync (detailPage);
			}
		}
 async void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
 {
     if (listView.SelectedItem != null)
     {
         var detailPage = new DetailPage();
         detailPage.BindingContext = e.SelectedItem as Contact;
         listView.SelectedItem     = null;
         await Navigation.PushModalAsync(detailPage);
     }
 }