Left margin left pattern is a technique to create 2 blocks side by side. The left block has a fixed size and the right block will take the rest of the available space. When the user resizes the browser, the added or removed space will be taken from the right block.

<div class="Parent">

  <div style="float: left; width: 100px">

  </div>

  <div style="margin-left: 105px;">

  <div>

  <div style="clear: left"><span></span></div>

</div>