Is it necessary to manually set the height of a div that contains an unordered list?
In my current setup, main1 and main2 divs overlap if I don't specify the height. Are there alternative methods to prevent this overlapping without setting a fixed height?
<div id='main1'>
<ul>
<li> </li>
<li> </li>
<li> </li>
</ul>
</div>
<div id='main2'>
<ul>
<li> </li>
<li> </li>
<li> </li>
</ul>
</div>