private void newToolStripMenuItem_Click(object sender, EventArgs e)
        {
            InputWindow input = new InputWindow(null);

            //registe InputWindow custom events
            input.ApplyShip += Input_ApplyShip;
            input.NewShip   += Input_NewShip;
            input.ShowDialog(this);
        }
        //event when user double click on listview row
        private void lvDisplay_DoubleClick(object sender, EventArgs e)
        {
            var selectedItem = lvDisplay.SelectedItems[0];

            //get spaceship model from tag
            SpaceShip model = (SpaceShip)selectedItem.Tag;

            //display dialog
            InputWindow input = new InputWindow(model);

            //register InputWindow custom events
            input.ApplyShip += Input_ApplyShip;
            input.NewShip   += Input_NewShip;
            input.ShowDialog(this);
        }