Need help ...Enter need to disable in asp:AutoCompleteExtender search textbox

HI Team,


I have asp:AutoCompleteExtender on my page . The user is typing 1 word and heating enter button. Enter generating post back and text box list of search items are disappearing from page. I want to disable the enter button and list of search item should appear in textbox. How i can do that. I tried follow code.

http://stackoverflow.com/questions/14857666/preventing-enter-from-picking-an-item-from-an-auto-complete-list-to-close-moda

<div class="SearchBox">
<div style="float: left"><asp:TextBox ID="txtSubtopic" runat="server" Width="240px" ClientIDMode="Static"></asp:TextBox></div><asp:AutoCompleteExtender ID="AutoCompleteExtender1" TargetControlID="txtSubtopic"
                                        runat="server" ServiceMethod="GetCompletionListAll" EnableCaching="true" OnClientItemSelected="txtsubtopic_item_selected"
                                        UseContextKey="True" MinimumPrefixLength="1" CompletionSetCount="100" CompletionListCssClass="CompletionListCssClass"
                                        FirstRowSelected="true"></asp:AutoCompleteExtender><asp:TextBoxWatermarkExtender ID="tbwmExt" runat="server" BehaviorID="txtSubtopic"
                                        TargetControlID="txtSubtopic" WatermarkText="Search data by keyword (ie. Asthma)"
                                        WatermarkCssClass="WaterMarkSearch" /></div>

function txtsubtopic_item_selected(source, eventArgs) {
            var route = window.location.href;
            var routeData = route.split("?")[0];
            window.location.href = routeData + "?" + eventArgs.get_value();

        }


        $(function () {$('#txtSubtopic').bind('keydown', function (e) {
                debugger;
                if (e.keyCode == 13) {
                    if ($('#txtSubtopic')._selectIndex !== -1) {$('#txtSubtopic')._setText($('#txtSubtopic')._completionListElement.childNodes[$('#txtSubtopic')._selectIndex]);
                        ev.stopPropagation(); // added line
                        ev.preventDefault();
                        alert("ale");
                    } else {
                        // close the popup
                        this.hidePopup();
                    }
                }
            });
        });

Thank You in an advance.

Vishal bedre