public MainWindow(string login)
 {
     InitializeComponent();
     pf = new PreferenceUtilisateur(login);
     if (pf.Load(login))
     {
         this.Top = pf.PosX;
         this.Left = pf.PosY;
         this.Height = pf.HeightMainWindow;
         this.Width = pf.WidthMainWindow;
     }
 }