<ul>
<li>
<a onclick="showChildren()" >item</a>
<ul style="display: none;">
<li>
some content...
</li>
</ul>
</li>
</ul>
when I scroll bottom it's fine, but if I click one item, the children ul will display, and the displayed ul will overlay on the bottom, the ul part can't be scrolled.
How I can make the ul display and increase the scroll height?