How to hide TabPageAdv when TabPageAdvCollection count is reduced to one in WinForms TabControlAdv?

private void tabControlAdv1_SelectedIndexChanged(object sender, EventArgs e)
{
   if(tabControlAdv1.TabCount == 1)
   {
      tabControlAdv1.SelectedTab.TabVisible = false;
   }
}
private void button1_Click(object sender, EventArgs e)
{
   tabControlAdv1.SelectedTab.TabVisible = true;
   TabPageAdv page = new TabPageAdv();
   page.Text = "NewTab";
   tabControlAdv1.TabPages.Add(page);
}

Private Sub tabControlAdv1_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs) Handles tabControlAdv1.SelectedIndexChanged
   If tabControlAdv1.TabCount = 1 Then
      tabControlAdv1.SelectedTab.TabVisible = False
   End If
End Sub
Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
   tabControlAdv1.SelectedTab.TabVisible = True
   Dim page As New TabPageAdv()
   page.Text = "NewTab"
   tabControlAdv1.TabPages.Add(page)
End Sub