usa i div.

crei un box, dove inserisci 2 div

e dai lo stile tramite css
HTML---->
<body>
<div class="box">
<div class="sx"></div>
<div class="dx"></div>
</div>

</div>
</body>
CSS---->
.box{
height:500;
width:500;
margin:auto;
}

.sx{
float:left;
height:500;
width:200;
}

.dx{
float:right;
height:500;
widht:300;
}