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