Spinner with valueUpdate

How to make knockout-spinner update when spinner buttons are pressed

HTML

<script src="http://knockoutjs.com/downloads/knockout-3.2.0.js"></script>
<input id="infoX"  data-bind="spinner: infoXpos, spinnerOptions: { min: -50, max: 50 }, valueUpdate: ['propertychange','input']"  />
<br>
    Xpos=<span data-bind="text: infoXpos"></span>
<hr/>
<input id="infoX"  data-bind="spinner: infoXpos, spinnerOptions: { min: -50, max: 50 }, valueUpdate: 'keyUp'"  />
<br>
    Xpos=<span data-bind="text: infoXpos"></span>
<hr/>

JavaScript

ko.bindingHandlers.spinner = {
        init: function (element, valueAccessor, allBindingsAccessor) {
            //initialize datepicker with some optional options
            var options = allBindingsAccessor().spinnerOptions || {};

            //handle the field changing
            ko.utils.registerEventHandler(element, "spinstop", function () {
                var observable = valueAccessor();
                observable($(element).spinner("value"));
            });

            //handle disposal (if KO removes by the template binding)
            ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
                $(element).spinner("destroy");
            });

            $(element).spinner(options);

        },
        update: function (element, valueAccessor) {
            var value = ko.utils.unwrapObservable(valueAccessor()),
                current = $(element).spinner("value");

            if (value !== current) {
                $(element).spinner("value", value);
            }
        }
    };

viewModel = function(){
    var self = this;
    
    self.infoXpos = ko.observable(7);
};


ko.applyBindings( new viewModel() );