title: How to set scroll height?
body: <pre><code>+-------------+      +---------------------------------+
  |             |      |                                 |
  |     1       |      |                                 |
  | left-nav    |      |                                 |
  |             |      |                                 |
  +-------------+      |               3                 |
  |             |      |                                 |
  |             |      |                                 |
  |     2       |      | very long contents here         |
  |             |      | which causes to scroll          |
  |   other     |      | vertical bar. Setting           |
  | remaining   |      | this content to 100% height?    |
  +-------------+      +---------------------------------+
  </code></pre>
  
  <p>What is height: 100%; actually? Is it applied to a page window or till the scroll ends?
  I have following html...</p>
  
  <pre><code>&lt;div id="wrapper"&gt;
  &lt;div id="left-nav"&gt;
  &lt;!--contents of 1--&gt;
  &lt;/div&gt;
  &lt;div id="yourad"&gt;
  &lt;!--contents of 2---&gt;
  &lt;/div&gt;
  &lt;div id="main-contents"&gt;
  &lt;!--contents of 3--&gt;
  &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>My css is as follows....</p>
  
  <pre><code>#wrapper{position: relative; width: 1007px; margin: 0 auto;}
  #left-nav{width: 329px; height: 100%; background: grey;float: left;}
  #yourad{height: 100%; background: blue;}
  #main-contents{margin-left: 329px; padding: 10px; background: pink;}
  </code></pre>
  
  <p>****Note: **** </p>
  
  <p>First see my demo to understand my problem <strong><a href="http://jsfiddle.net/Y7PhV/99/" rel="nofollow">Here</a></strong></p>
  
  <p>Contents of 1 actual height: I don't know.</p>
  
  <p>Contents of 2 actual height: I dont't know.</p>
  
  <p>Contents of 3 actual height: I don't know.</p>
  
  <p>Because I may need for some pages less contents and some pages more contents.</p>
  
  <p>I've tried by using <code>height: 100%;</code>  in html, body, wrapper, left-nav, yourad, but could not success.</p>