knockjs custom binding to use the jquery slider

knockoutjs_jquery_slider.js

 // usage: <td data-bind="jqSlider: points"></td>
 
ko.bindingHandlers.jqSlider = {
    init: function(element, valueAccessor) {
       $(element).empty().slider({
            range: "min",
            min: 0,
            max: 5,
           change:function( event, ui ) {
                var observable = valueAccessor();
                observable(ui.value); 
              }
       });
    },
    update: function(element, valueAccessor) {
        // Give the first x stars the "chosen" class, where x <= rating
        var value = valueAccessor();
        var valueUnwrapped = ko.utils.unwrapObservable(value); 
        alert("observable: " +  valueUnwrapped);
        $(element).slider( "value", valueUnwrapped); 
    }
};