private void btnAddOrder_Click(object sender, EventArgs e)
        {
            Order order1 = new Order();

            order1.CustomerID   = cmbCustomer.SelectedValue.ToString();
            order1.EmployeeID   = Convert.ToInt32(cmbEmployee.SelectedValue);
            order1.OrderDate    = dtpOrderDate.Value;
            order1.RequiredDate = dtpRequiredDate.Value;
            order1.ShipVia      = Convert.ToInt32(cmbShipVia.SelectedValue);
            order1.Freight      = Convert.ToDecimal(txtFreight.Text);
            db.Orders.Add(order1);
            db.SaveChanges();

            FormOrderHeaderDetail frmOrderDetails = new FormOrderHeaderDetail(order1.OrderID);

            frmOrderDetails.Show();
            this.Hide();
        }
 private void btnOpenOrder_Click(object sender, EventArgs e)
 {
     selectedOrderID = Convert.ToInt32(txtOrderID.Text);
     try
     {
         var conditional = db.Orders.Where(x => x.OrderID == selectedOrderID).ToList();
         if (conditional.Count == 0)
         {
             MessageBox.Show("This ID is not avaible");
         }
         else
         {
             FormOrderHeaderDetail formOrderDetails = new FormOrderHeaderDetail(selectedOrderID);
             formOrderDetails.Show();
             this.Hide();
         }
     }
     catch
     {
         MessageBox.Show("Incorrect Format");;
     }
 }