title: Prevent declaring variables without var
body: <p>How can I prevent variables from being declared without using the <code>var</code> keyword? Can I set NetBeans to warn me about this?</p>
  
  <p>For example, I want a warning or something on this:</p>
  
  <pre><code>var testing = 5;
  
  // ...
  
  testin = 2; // Woops, typo!
  </code></pre>