请前辈们帮忙解决下面的VB.NET问题？

在窗体中设置了两个textbox文本框和一个按钮button，下面请前辈们看看以下这些窗体form中的代码：
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
If TextBox1.Text <> "0" Then
TextBox2.Enabled = False
TextBox2.Text = "0"
End If
End Sub

Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.TextChanged
If TextBox2.Text <> "0" Then
TextBox1.Enabled = False
TextBox1.Text = "0"
End If
End Sub

Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button.Click
TextBox1.Enabled = True
TextBox2.Enabled = True
TextBox1.Text = ""
TextBox2.Text = ""

End Sub

我本想实现单击按钮button能清除和恢复textbox1和textbox2文本框的内容和可用性，可是运行后在任意一个文本框中输入数字后单击button按钮却没有使两个textbox都恢复原样！就如我在textbox1中输入520，textbox2不能用了，点击按钮可textbox2还是不能用哈！请前辈们帮忙解决下哦，非常感谢了！