[color=#FF0000]var ActionItemModule = (function () {[/color]
    var newAIID = 0; //new action item id
    var dataReadyFlag = false;
    return {
      [color=#FF0000]  setData:[/color] function (data) {
            setActionItems(data["actionitems"]);
        },
        [color=#FF0000]getData:[/color] function () {
            return getActionItems();
        },
       [color=#FF0000] validateData:[/color] function () {
            return checkActionItems();
        },
        addRow: function () {
            addActionItem();
        },
        removeRow: function () {
            removeActionItem();
        },
        setWorkMode: function (mode) {
            if (!dataReadyFlag) {
                setTimeout("ActionItemModule.setWorkMode('" + mode + "')", 500);
                return;
            }
            doSetWorkMode(mode);
        }
    };

打个比方：
var jQuerys = (function () {
    return { setData: function () { alert("11111") } }
})();
alert(jQuerys.setData());
//你看下 这个就可以好理解啦吧