public AdminGenerateRequier()
 {
     try
     {
         centers  = controller.GetDBCenters();
         products = controller.GetDBProducts();
         InitializeComponent();
         FromCenter.ItemsSource       = centers;
         FromCenter.DisplayMemberPath = "CenterName";
         ToCenter.ItemsSource         = centers;
         ToCenter.DisplayMemberPath   = "CenterName";
         Products.ItemsSource         = products;
         Products.DisplayMemberPath   = "Name";
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }