title: Problems with setInterval
body: <p>I am just trying to implement the most basic example of setInterval with jQuery and am having problems. What's wrong here?</p>
  
  <p>It says function rotate is not defined.</p>
  
  <pre><code>$(document).ready(function() {
      var speed = 5000;
      var run = setInterval("rotate()", speed);
  
      function rotate() {
          alert ('rotate');
      }
  });
  </code></pre>