请教ajax的问题

Question

请帮我解释下，这段ajax的代码哦
<TD>
<input autocomplete="off" type="text" name="query" id="zip" style="width:315px;" class="wd" value="<%=query%>"/>
<div class="auto_complete" id="zip_values"></div>
              <script type="text/javascript">
           new Ajax.Autocompleter('zip', 'zip_values',
                                 'autoComplete', {afterUpdateElement : getSelectionId});
                  function getSelectionId(text, li) {
window.location = "./index.jsp?query="+encodeURIComponent(text.value);
}
              </script>
</TD>

Answer 1

Autocompleter(
'zip'//变量参数, 
'zip_values'//变量参数, 
 'autoComplete'//变量参数, 
{afterUpdateElement//变量参数:getSelectionId//function()}// 作为一个参数类似于case:);