How to stop my simple animation by pressing a button

I use following code to do a simple animation. But I want to use an button (when pressing it) to stop the animation when the pictureBox is still moving.

So, how I can do it?

Thanks.

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
               Dim t As Integer
        t = 0
        For t = 1 To 80

                Me.PictureBox1.Refresh()
                Me.PictureBox1.Top = Me.PictureBox1.Top - 1
                System.Threading.Thread.Sleep(300)

        Next t
        Timer1.Enabled = False
    End Sub