title: Background image in id selector not showing up
body: <p>I cannot get this background image to appear. It is supposed to appear in the background with the header overlapping it. I'm using an id selector. I literally copied this straight from the book i have for my class and it's not working at all. </p>
  
  <p>Here is my code. I'm very new to css</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
  &lt;title&gt;Fall Nature Hikes&lt;/title&gt;
  &lt;style&gt;
  #content { background-image: url(fall.jpg);
  background-repeat: no-repeat;
  margin-left: auto;
  margin-right: auto;
  width: 640px;
  height: 480px;
  padding-top: 20px; } 
  
  h1 { background-color: #FFFFFF;
  opacity: 0.6;
  font-size: 4em;
  padding: 10 px; } 
  &lt;/style&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div id="content"&gt;
  &lt;h1&gt;Fall Nature Hikes&lt;/h1&gt;
  &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>