jQuery: getting level of selected li

i'm working with wordpress+jQuery - there's a navigationscript (it's an UL) with several levels like this:

<ul>
<li>level 1 - item1</li>
<li>level 1 - item2
    <ul>
        <li>level 2 - item1</li>
        <li class=current_page_item>level 2 - item开发者_开发知识库2</li>
    </ul>
</li>
<li>level 1 - item3</li>
</ul>

wordpress is applying a css-class called current_page_item to the current LI. my question: when selecting that LI - how can i find out it's level in the UL? (in my case: level 2)

By counting its parents:

$('.current_page_item').parents('ul').length;

var selectedItem = $('.current_page_item');
var Index = $("li", "ul").index(selectedItem);

Index gives you the index of that class..