VB.net中在窗体设置一个标签，让他沿窗体八字形滚动，如何让他一接触边框便折返

RT，现在是沉下去老久才会上来
Public Class Form1
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Timer1.Enabled = False
Label1.Top = 0
Label1.Left = 0
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Timer1.Enabled = True
End Sub

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    Call mymove()
End Sub

Sub mymove()
    Static m As Double
    m = (Me.Height - Label1.Height) / (Me.Width - Label1.Width)
    Timer1.Interval = Val(TextBox1.Text)
    Dim x As Double, y As Double
    Static flag As Integer
    If (Label1.Top <= 0 And Label1.Left <= 0 Or Label1.Top <= 0 And Label1.Left >= Me.Width - Label1.Width) Then
        flag = 0
    ElseIf (Label1.Top >= Me.Height - Label1.Height And Label1.Left <= 0) Then
        flag = 1
    ElseIf (Label1.Top >= Me.Height - Label1.Height And Label1.Left >= Me.Width - Label1.Width) Then
        flag = 2
    End If
    Select Case flag
        Case 0
            x = 100 * m
            y = 0
        Case 1
            x = -100 * m
            y = 100
        Case 2
            x = -100 * m
            y = -100
    End Select
    Label1.Top += x
    Label1.Left += y
    Label2.Text = x
    Label3.Text = y
End Sub

End Class

Label1.Top >= Me.Height - Label1.Hight加入条件

timer定时，移动控件。。。