Partial-page rendering removes the need for the whole page to be
refreshed during postback. To do this, put the components under ContentTemplate as follow:
<asp:UpdatePanel ID="updatePanel" runat="server">
<ContentTemplate>
.
.
.
</ContentTemplate>
</asp:UpdatePanel>
<asp:UpdatePanel ID="updatePanel" runat="server">
<ContentTemplate>
.
.
.
</ContentTemplate>
</asp:UpdatePanel>