How do I get a button that is inside an asp:UpdatePanel to update the whole page?

<asp:UpdatePanel ID="myFirstPanel" runat="server" ChildrenAsTriggers="false" UpdateMode="Conditional">
   <ContentTemplate>
      <asp:Button runat="server" ID="myFirstButton" Text="My First Button" onclick="myFirstButton_Click" />
      <asp:Button runat="server" ID="mySecondButton" Text="My Second Button" onclick="mySecondButton_Click" />
   </ContentTemplate>
</asp:UpdatePanel>

<asp:UpdatePanel ID="mySecondPanel" runat="server">
   <ContentTemplate>
       <asp:Label runat="server" ID="myFirstLabel" Text="My First Label"></asp:Label>
    </ContentTemplate>
    <Triggers>
       <asp:AsyncPostBackTrigger ControlID="myFirstButton" EventName="Click" />
    </Triggers>
</asp:UpdatePanel>
<asp:Label runat="server" ID="mySecondLabel" Text="My Second Label"></asp:Label>

protected void myFirstButton_Click(object sender, EventArgs e)
{
  myFirstLabel.Text = "Inside Panel " + DateTime.Now.ToString("mm:ss");
}
protected void mySecondButton_Click(object sender, EventArgs e)
{
  mySecondLabel.Text = "Outside Panel " + DateTime.Now.ToString("mm:ss");
}

<Triggers>
   <asp:PostBackTrigger ControlID="mySecondButton" />
</Triggers>