The left column is absolutly positioned and is a fixed width. It won't move.
The content column, which you are reading from, is flexible. It will automatically change shape, width can be controlled by setting appropriate margins or an actual width can be specified if required.
CSS::
#lh-col{ position: absolute; top: 20px; left: 20px; width: 180px; border: 2px solid #000000; background: #c0c0c0; color: #333333; margin: 0px; padding: 0px; height: 400px; } #rh-col{ margin: 20px 20px 20px 220px; border: 2px solid #000000; background: #ffffff; color: #333333; padding: 20px; }