title: Define global if it doesn't exist
body: <p>I'm trying to set a global if it doesnt exist. Total noob question.</p>
  
  <p>I'm doing this:</p>
  
  <pre><code>if (!raw) {
     raw = 'yep';
  }
  </code></pre>
  
  <p>But it keeps throwing reference error raw is not defined.</p>