How To Call Server Side Code From AJAX client-side

In the AutoCompleteExtender OnClientItemSelected property add the JavaScript method to be called: OnClientItemSelected=”AutoCompletedClientItemSelected”
Within the AutoCompletedClientItemSelected JavaScript method issue a __doPostBack(“AutoCompleteExtender”, sender._element.value); which will induce the postback to the server.

view sourceprint?

01	<script language="javascript" type="text/javascript">

02	// postBack handler for AJAX AutoComplete Extender - onClientItemSelected

03	function AutoCompletedClientItemSelected(sender, e) {

04	__doPostBack("AutoCompleteExtender", sender._element.value);

05

}

06

07

</script>

08

09	<div id="find">

10	<div id="findbox">

11	<span class="label">JHA Name</span>

12	<asp:TextBox ID="tbJHAName" CssClass="namebox" runat="server" AutoComplete="Off"

13	Width="550px" Style="margin-top: 0px"></asp:TextBox>

14

</div>

15	<asp:AutoCompleteExtender ID="tbJHAName_AutoCompleteExtender" runat="server" Enabled="true"

16	ServicePath="" ServiceMethod="GetJHANames" TargetControlID="tbJHAName" MinimumPrefixLength="3"

17	UseContextKey="True" OnClientItemSelected="AutoCompletedClientItemSelected">

18	</asp:AutoCompleteExtender>

19	<a id="linkAdvancedSearch" class="advancedlink" href="Javascript:void(0)" onclick="ShowAdvanced(this);">

20	Advanced Search</a>

21

</div>

Code Behind Page:
Filter the EventTarget message sent from the JavaScript method in the Page_Load event.

view sourceprint?

01	protected void Page_Load(object sender, EventArgs e)

02

{

03	if (IsPostBack)

04

{

05	// postBack handler for AJAX AutoComplete Extender - JavaScript call: AutoCompletedClientItemSelected

06	if (Request.Form["__EVENTTARGET"] != null &&

07	Request.Form["__EVENTTARGET"] == "AutoCompleteExtender" &&

08	Request.Form["__EVENTARGUMENT"] != null)

09

{

10	// Emulate button click search

11	btnSearch_Click(null, null);

12

13

}

14

}