Timer in wpf

public partial class MainWindow : Window
    {
        System.Timers.Timer   t=new   System.Timers.Timer();
                              t.Interval=5000;
         
        public MainWindow()
        {
            this.InitializeComponent();            
            // Insert code required on object creation below this point.
        }
        
   private void Button1_Click(object sender, System.Windows.RoutedEventArgs e)
        {            
            this.media1.Play();
            //mel_Copy.Stop();
            
            t.Enabled=true;
            t.Tick+=new System.EventHandle(this.timer1_Tick);    //here        
            
            //B1
        }

       private void timer1_Tick(object sender, System.EventArgs e)   
                  {
    this.media1.Stop();    
                    }
        }
}