I need to have the contextKey determined by a TextBox.  I am trying the approach by kirtid.

function AutoCompleteContextKeys() {
		

	var autoComplete = $find('autoCompleteState');
	var autoComplete2 = document.getElementById('<%= this.autoCompleteState.ClientID %>');
			

	if (autoComplete == null)
		alert("autoComplete is null");
				

	if (autoComplete2 == null)
		alert("autoComplete2 is null");
	

	if (!autoComplete) return;
		var target = autoComplete.get_element();
	if (!target) return;
		var userContext = $get('edtCountry');
	if (!userContext) return;


	// Dynamically assign the context
	autoComplete.add_populating(
		function()
		{
			autoComplete.set_contextKey(userContext.value);
		});


}


addLoadEvent(AutoCompleteContextKeys);


...


<asp:TextBox runat="server" ID="edtState" CssClass="EditBox" Width="350px" />
<ajax:AutoCompleteExtender ID="autoCompleteState" runat="server" ServiceMethod="State" ServicePath="../../API/AutoComplete.asmx" TargetControlID="edtState"  MinimumPrefixLength="1" CompletionInterval="250" EnableCaching="true" CompletionSetCount="20" FirstRowSelected="true" UseContextKey="true"
													CompletionListCssClass="AutoComplete_List ACL_Width200" CompletionListItemCssClass="AutoComplete_Item" CompletionListHighlightedItemCssClass="AutoComplete_ItemSelected"></ajax:AutoCompleteExtender>
											

<asp:TextBox runat="server" ID="edtCountry" CssClass="EditBox" Width="350px" />

Both autoComplete and autoComplete2 are null.

What am I doing wrong?