title: action keyup after the third charecter
body: <p>Hi could someone help me figure out how to stop a function running until a specific number of characters are pressed?  </p>
  
  <p>currently using the following function:</p>
  
  <pre><code>$('input#q').keyup
  </code></pre>
  
  <p>this works as soon as you press any key...</p>