private void Add_User(object sender, RoutedEventArgs e)
 {
     //addUser addUser = new addUser();
     //addUser.Show();
     //addUser.Closed += (s, eventarg) =>
     //{
     //    LoadCompaniesList();
     //}
     if (invoiceOpen)
     {
         NewInvoice newInvoice = new NewInvoice();
         newInvoice.Show();
         newInvoice.Closed += (s, eventarg) =>
         {
             LoadInvoicesList();
         };
     }
     if (StorageOpen)
     {
         AddNewProductMagazine addNewProductMagazine = new AddNewProductMagazine();
         addNewProductMagazine.Show();
         addNewProductMagazine.Closed += (s, eventarg) =>
         {
             LoadProductsList();
         };
     }
     if (SettlementsOpen)
     {
     }
     if (ContractorsOpen)
     {
         AddNewSeller addNewSeller = new AddNewSeller();
         addNewSeller.Show();
         addNewSeller.Closed += (s, eventarg) =>
         {
             LoadSellersList();
         };
     }
     if (StatmentsOpen)
     {
     }
 }
        private void generate_Invoice(object sender, RoutedEventArgs e)
        {
            NewInvoice newInvoice = new NewInvoice();

            newInvoice.Show();
        }