How to stretch the width of an element, so that it is (100% - widths of its siblings)?

http://stackoverflow.com/questions/3682649/how-to-stretch-the-width-of-an-element-so-that-it-is-100-widths-of-its-sibl

by Wexcode

HTML

<ul>
  <li>
      <input class="btn" type="button" value="Submit"/>
      <div class="inputbox"><input id="textField" type="text" /></div>
  </li>
</ul>

CSS

ul { 
    list-style: none; 
    padding: 0; }
.btn { float: right; }
.inputbox { 
    padding: 0 5px 0 0;
    overflow: hidden; }
.inputbox input { width: 100%; }