/// <summary>
        /// Modifies a bike with an existing Id
        /// </summary>
        private void ModifyBike(Bike bikeToUpdate, BikeStock stockToUpdate)
        {
            // Update frame size combo
            if (FrameSizeCombo.SelectedIndex != -1 && FrameColourCombo.SelectedIndex != -1)
            {
                bikeToUpdate.Size   = FrameSizeCombo.Text;
                bikeToUpdate.Colour = FrameColourCombo.Text;
                bikeToUpdate.UpdateFrame(FrameSizeCombo.Text, FrameColourCombo.Text, stockToUpdate);
            }

            // Update wheels from combo
            if (WheelsCombo.SelectedIndex != -1)
            {
                bikeToUpdate.Wheels = WheelsCombo.Text;
                bikeToUpdate.UpdateWheels(WheelsCombo.Text, stockToUpdate);
            }

            // Update gears from combo
            if (GearCombo.SelectedIndex != -1 && BrakeCombo.SelectedIndex != -1)
            {
                bikeToUpdate.Gears  = GearCombo.Text;
                bikeToUpdate.Brakes = BrakeCombo.Text;
                bikeToUpdate.UpdateGroupSet(GearCombo.Text, BrakeCombo.Text, stockToUpdate);
            }

            // Update handlebars from combo
            if (HandlebarCombo.SelectedIndex != -1 && SaddleCombo.SelectedIndex != -1)
            {
                bikeToUpdate.Handlebars = HandlebarCombo.Text;
                bikeToUpdate.Saddle     = SaddleCombo.Text;
                bikeToUpdate.UpdateFinishingSet(HandlebarCombo.Text, SaddleCombo.Text, stockToUpdate);
            }

            // If a warranty has been added
            if (WarrantyBox.IsChecked == true)
            {
                bikeToUpdate.AddWarranty();
            }

            bikeToUpdate.UpdatePrice();

            // Updates the display fields
            UpdateText(bikeToUpdate, stockToUpdate);
        }