Clearing a Typeahead if no value is selected from the dropdo

Question

I use typeahead.js as autocomplete textbox.

 

when I input and select a value from the suggestions, textbox and hiddenfield sets the value correctly. But when I input a value and loose focus of textbox without selecting textbox value and hiddenfield value are missmatch.

 

How do I clear the value of the textbox and hiddenfield when the input value is not selected from suggestions.

$(function () {
    $('#txtCustomer').typeahead({
        hint: true,
        highlight: true,
        minLength: 1,
        source: function (request, response) {
            $.ajax({
                url: '/Customer.aspx/GetCustomers',
            data: "{ 'prefix': '" + request + "'}",
            dataType: "json",
            type: "POST",
            contentType: "application/json; charset=utf-8",
            success: function (data) {
                items = []; map = {};
                var obj = JSON.parse(data.d);
                $.each(obj.Data, function (i, value) {
                    map[name] = { id: value.CustomerID, name: value.FullName };
                    items.push(map[name]);
                });
                response(items);
            },
            error: OnError,
            failure: OnError,
        });
    },
    updater: function (item) {
        $('#hfCustomerId').val(item.id);
        return item;
    }
});
});