<!DOCTYPE HTML>
<html>
<body>
<fieldset style="position:relative; overflow:hidden; width:500px; height:500px;">
<legend>Legend</legend>
<div style="height:1000px;">
<div style="position:absolute; padding:2px; left:20px; top:20px; background:yellow;">Abs-pos</div>
</div>
</fieldset>
</body>
</html>