<style>
#b2-Column1 {
background-color:red;
min-height:120px;
}
#b2-Column1 > div {
background-color:yellow;
min-height:100px;
}
</style>
<div id="b2-Column1">
<div><!-- some comments here's --></div>
</div>
How can I do, if the yellow section is empty, then I want to both red and yellow setting to display:none;