//Get request to get the page of the selected donation
        //URL: Donations/Update/1
        public ActionResult Update(int id)
        {
            //find the donation in the db
            var donation = db.Donations.SingleOrDefault(d => d.Id == id);
            //set the viewModel for the update page: Display foreign keys(Provinces , Designations)
            var viewModel = new NewDonationViewModel
            {
                Donation     = donation,
                Designations = db.Designations.ToList(),
                Provinces    = db.Provinces.ToList()
            };

            //display the update donation page
            return(View("Update", viewModel));
        }
        //Get the Add page: this only shows the Add page
        //with populated provinces and designations from other tables
        public ActionResult Add()
        {
            //to use the dbcontext we need to define it at the top of the controller
            //dbsets have been already added to the dbcontext file
            //we need a viewModel because this is a list from another table
            var provinces    = db.Provinces.ToList();
            var designations = db.Designations.ToList();

            //initialize the viewmodel
            var viewModel = new NewDonationViewModel
            {
                Provinces    = provinces,
                Designations = designations
            };

            //pass the viewModel to the view
            return(View(viewModel));
        }