How to close modalpopupextender in usercontrol that is used twice in one page when esc key is pressed?

<script type="text/javascript">

    function pageLoad(sender, args) {
        if (!args.get_isPartialLoad()) {
            $addHandler(document, "keydown", onKeyDown);
        }
    }

    function Hide(controlID) {
        var mpe = $find(controlID);
        mpe.hide();
        var mpe = $find('ModalPopupExtender1');
        mpe.hide();
    }
    function onKeyDown(e) {
        if (e && e.keyCode == Sys.UI.Key.esc) {
            Hide(document.getElementById("<% =ModalPopupExtender1.ClientID%>"));
        }
    }
</script>Close with escape key ajax ModalPopupExtender not working

in two days of searching I can't still find any answer for this.

Anyway, I have modal pop up extender in usercontrol then I used my user control twice in one page.

My problem is I can't close it with esc key is click with the code above. it always null or cant find something.

Then, I tried using behaviorID but it cannot be done too.

    function pageLoad(sender, args) {
        if (!args.get_isPartialLoad()) {
            $addHandler(document, "keydown", onKeyDown);
        }
    }


    function onKeyDown(e) {
        if (e && e.keyCode == Sys.UI.Key.esc) {
            $find('bhiModalPopupExtender1').hide();
        }
    }


<cc1:ModalPopupExtender ID="ModalPopupExtender1" runat="server" PopupControlID="Panel1" TargetControlID="hdnModalPopup" BehaviorID="bhiModalPopupExtender1"
    CancelControlID="hdnModalPopup" BackgroundCssClass="modalBackground">
</cc1:ModalPopupExtender>Thanks for helping.