C#

private Graphics panelGraphics = null;
private Pen panelPen = null;
private Point oldPosition;
private bool init=false;
private void panel2_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
    if(panel2.BackgroundImage==null)
    {
        panel2.BackgroundImage= new Bitmap(panel2.Width, panel2.Height);
    }
    if(panelGraphics==null)
        panelGraphics = Graphics.FromImage(panel2.BackgroundImage);

    if(panelPen==null)
        panelPen= new Pen(Color.Red,2);

    if(init)
    {
        Point newPostion = new Point(e.X,e.Y);
        panelGraphics.DrawLine(panelPen, oldPosition, newPostion);

        Refresh();
    }
    else
        init=true;

    oldPosition = new Point(e.X,e.Y);
}

panelGraphics.Dispose();
panelPen.Dispose();

<br />
[XmlIgnore()]<br />
public List vehicles<br />

<parking><br />
  <vehicles><br />
     .... all vehicules (classes Car, Truck, Motorbike ...)<br />
  </vehicles><br />
</parking><br />

    //constructor code
    this.KeyPreview = true;
}
 
protected override void OnKeyPress(KeyPressEventArgs e)
{
    if(e.KeyChar.Equals('X')||e.KeyChar.Equals('x'))
	Close();
    else
        base.OnKeyPress (e);
}