<section class=\"main\">
 <div class=\"wrapper-demo\">
 <div id=\"dd\" class=\"wrapper-dropdown-1\" tabindex=\"1\">
 <span>手册网</span>
 <ul class=\"dropdown\" tabindex=\"\">
 <li><a href=\"#\">jQuery特效</a></li>
 <li><a href=\"#\">网站模板</a></li>
 </ul>
 </div>
 </div>
 </section>
</div>
<script type=\"text/javascript\" src=\"http://libs.useso.com/js/jquery/1.7.2/jquery.min.js\"></script>
<script type=\"text/javascript\">
 function DropDown(el) {
 this.dd = el;
 this.placeholder = this.dd.children(\'span\');
 this.opts = this.dd.find(\'ul.dropdown > li\');
 this.val = \'\';
 this.index = -;
 this.initEvents();
 }
 DropDown.prototype = {
 initEvents: function() {
 var obj = this;
 obj.dd.on(\'click\', function(event) {
 $(this).toggleClass(\'active\');
 return false;
 });
 obj.opts.on(\'click\', function() {
 var opt = $(this);
 obj.val = opt.text();
 obj.index = opt.index();
 obj.placeholder.text(\'Gender: \' + obj.val);
 });
 },
 getValue: function() {
 return this.val;
 },
 getIndex: function() {
 return this.index;
}
 }
 $(function() {
 var dd = new DropDown($(\'#dd\'));
 $(document).click(function() {
 $(\'.wrapper-dropdown-1\').removeClass(\'active\');
 });
 });
</script>