使用History.js后退按钮不起作用？

Question

我在这里使用History.js https://github.com/browserstate/history.js/

这就是我目前所拥有的：

    var History = window.History;
    if (History.enabled) {
        // set initial state for first page that is loaded
        var State = History.getState();
        History.pushState({urlPath: window.location.pathname}, $("title").text(), State.urlPath);
    } 
    else {
        return false;
    }

    // content update and back/forward button handler
    History.Adapter.bind(window, 'statechange', function(){
        var s = History.getState();
        History.log(s.data, s.title, s.url);

        // update view based on load type
        OnLoadPageByURL(s.data.urlPath);
    });

    // navigation link handler(s)
    $('body').on('click', 'a', function(e){
        e.preventDefault();

        var load = $(e.currentTarget).data('load');
        var urlPath = $(this).attr('href');
        var title = $(this).text();

        History.pushState({ load: load, urlPath: urlPath }, title, urlPath);
    });

一切似乎都有效，但后退按钮似乎无法正常工作？我做错了什么？