How to retrieve the id of the <li> clicked to generate a popup

How to retrieve the id of the <li> clicked to generate a popup

Hello,I've a list composed like this:

<div data-role= collapsibleset id='CollAlim'>
<div data-role = collapsible>
<h3>collapsible header</h3>
<ul data-role='listview' id='listAl'>
<li><a href='#' detailId='101'></a></li>
<li><a href='#' detailId='102'></a></li>
<li><a href='#' detailId='103'></a></li>
<li><a href='#' detailId='104'></a></li>
<li><a href='#' detailId='105'></a></li>
<li><a href='#' detailId='106'></a></li>
</ul>
</div>
<div data-role = collapsible>
<h3>collapsible header2</h3>
<ul data-role='listview' id='listAl'>
<li><a href='#' detailId='107'></a></li>
<li><a href='#' detailId='108'></a></li>
<li><a href='#' detailId='109'></a></li>
<li><a href='#' detailId='110'></a></li>
<li><a href='#' detailId='111'></a></li>
<li><a href='#' detailId='112'></a></li>
</ul>
</div>
</div>

Could someone tell me how to retrieve the detailId of the <li> clicked to dynamically generate a new popup with the data corresponding on the detailId retrieved?

I've search and found a lot of different methods, but none works for me
Thanks in advance