Getting colours to fill columns using css

<div width="100%">
  <div class="leftnav">
    Navigation stuff goes here
  </div>
  <div class="bodytext">
    The main body text goes in here.  This is the heaps longer than the nav content
  </div>
  <div class="quicklinks">
    Some more stuff here
  </div>
</div>

.leftnav{
    position:absolute;
    top:50px;
    left:0px;
    width:150px;
    background-color:#ececdd;    
    }

.bodytext{
    position:absolute;
    top:60px;
    margin-left:165px;
    margin-right:160px;   
    }

.quicklinks{
    position:absolute;
    top:60px;
    right:5px;
    }