<!-- -->
<diV id="a" class="fluid_">
<Div class="sba">
a
</Div>
</diV>
<div class="clear"></div>
/* */
#a {background-color:transparent;} /* */
.sba {position:relative;left:0px;top:0px;margin:5px;}/* sub */
.sba {background:transparent;border: 1px solid red;}