You are implementing an ASP.NET AJAX page. You add the following control to the page.
<asp:UpdatePanel ID=”pnl1″ runat=”server” UpdateMode=”Conditional”>
<ContentTemplate> … </ContentTemplate>
</asp:UpdatePanel>
You need update the contents of the UpdatePanel without causing a full reload of the page. Which
two actions should you perform? (Each correct answer presents part of the solution. Choose two.)

A.
Add the following control before the UpdatePanel.
<asp:Timer ID=”Timer1″ OnLoad=”Timer1_Tick” runat=”server” Interval=”3000″ />

B.
Add the following control within the UpdatePanel.
<asp:Timer ID=”Timer1″ OnLoad=”Timer1_Tick” runat=”server” Interval=”3000″ />

C.
Add an AsyncPostBackTrigger that references Timer1.

D.
Add a PostBackTrigger that references Timer1.

Explanation:

AsyncPostBackTrigger defines a control and optional event of the control as an asynchronous
postback control trigger that causes an UpdatePanel control to refresh. PostBackTrigger defines a
control inside a UpdatePanel control as a postback control.
CHAPTER 9 Working with Client-Side Scripting, AJAX, and jQuery
Lesson 1: Creating AJAX-Enabled Web Forms
The UpdatePanel Control – Controlling partial-page updates (page 461)
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