width of Right Div = Width of container - width of left div - margin
1.) main container with clearfix class to fix the afterwards clear.
2.) main container has 2 div , left one with fixed width and right one with variable width.
3.) Left one uses float left to hang over on the left side where as right one uses margin to fix its width over the container.
so here is the code:
<style>
#LeftDiv{
float: left;
width: 150px;
background-color:red;
height: 150px;
}
#RightDiv{
background-color:fuchsia;
margin-left:160px;
height: 50px;
}
</style>
<div id="containerDiv" style="background-color:Lime; width: 1000px; margin: 0 auto;" class="clearfix">
<div ID="LeftDiv">
AAAA
</div>
<div ID="RightDiv">
BBBB
</div>
</div>
<div>
Here goes the footer
</div>