求解释这段代码！
<script src="js/jquery.min.js" type="text/javascript"></script>
  <script type="text/javascript">
var timeout = 500;
var closetimer = 0;
var ddmenuitem = 0;
function jsddm_open()
{ jsddm_canceltimer();
jsddm_close();
ddmenuitem = $(this).find('ul').eq(0).css('visibility', 'visible');}
function jsddm_close()
{ if(ddmenuitem) ddmenuitem.css('visibility', 'hidden');}
function jsddm_timer()
{ closetimer = window.setTimeout(jsddm_close, timeout);}
function jsddm_canceltimer()
{ if(closetimer)
{ window.clearTimeout(closetimer);
closetimer = null;}}
$(document).ready(function()
{ $('#jsddm > li').bind('mouseover', jsddm_open);
$('#jsddm > li').bind('mouseout', jsddm_timer);});
document.onclick = jsddm_close;
  </script>

------解决方案--------------------
又没有什么特殊代码。。
http://www.w3schools.com/jquery/html_appendto.asp
自己看吧。。