//
        // CTRL + Z
        //
        private void ctrl_Z(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Z && (e.Control))
            {
                EventState previousState = eventStates.Pop();
                this.personalGrid.inheritGrid(previousState.getLastPersonalGrid());
                this.battleShipsGRID.inheritGrid(previousState.getLastBattleshipGrid());
                this.clicks = previousState.getClicks();

                for (int i = 0; i < 5; i++)
                {
                    this.battleShipsGRID.tiles[0, i].ships = previousState.getLastBattleshipGrid().tiles[0, i].ships;

                    if (i == 0)
                    {
                        this.patrolNumberLabel.Text = previousState.getLastBattleshipGrid().tiles[0, i].ships.ToString();
                    }
                    if (i == 1)
                    {
                        this.cruiserNumberLabel.Text = previousState.getLastBattleshipGrid().tiles[0, i].ships.ToString();
                    }
                    if (i == 2)
                    {
                        this.valvetNumberLabel.Text = previousState.getLastBattleshipGrid().tiles[0, i].ships.ToString();
                    }
                    if (i == 3)
                    {
                        this.redNumberLabel.Text = previousState.getLastBattleshipGrid().tiles[0, i].ships.ToString();
                    }
                    if (i == 4)
                    {
                        this.dragonNumberLabel.Text = previousState.getLastBattleshipGrid().tiles[0, i].ships.ToString();
                    }
                }



                Console.WriteLine("CTRL + Z");
            }
        }