$(function() {
    var navigation = $('#nav-main').okayNav({
        beforeopen: function() {
            alert('beforeopen');
        },
        open: function() {
            alert('open');
        },
        beforeclose: function() {
            alert('beforeclose');
        },
        close: function() {
            alert('close');
        }
    });
});

<header id="header">
    <a class="site-logo" href="#">dowebok</a>

    <nav role="navigation" id="nav-main" class="okayNav">
        <ul>
            <li><a href="#">首页</a></li>
            <li><a href="#">代码</a></li>
            <li><a href="#">素材</a></li>
            <li><a href="#">模板</a></li>
            <li><a href="#">教程</a></li>
            <li><a href="#">关于</a></li>
            <li><a href="#">联系</a></li>
        </ul>
    </nav>
</header>