protected override void OnNavigatedTo(NavigationEventArgs e)
 {
     storedDonorList = e.Parameter as DonorManager;
 }
 protected override void OnNavigatedTo(NavigationEventArgs e)
 {
     //pass the object from the mainpage
     donorList = e.Parameter as DonorManager;
     Donors    = donorList.GetDonors();
 }