C# - Windows-Forms Panel frei positioniereren

Point position = new Point();
panel.MouseMove += new System.Windows.Forms.MouseEventHandler(this.panel_MouseMove);

private void panel_MouseMove( object sender, MouseEventArgs e )
{
    Panel p = sender as Panel;
    
    if ( e.Button == MouseButtons.Left )
    {
        Point mousePos = this.PointToClient( Control.MousePosition );
        if ( position.IsEmpty )
            position = new Point( mousePos.X - p.Left, mousePos.Y - p.Top );
        
        p.Location = new Point( mousePos.X - position.X, mousePos.Y - position.Y );
    }            
    else if ( !position.IsEmpty )
        position = new Point();
}