title: Using function as prototype
body: <p>Using JavaScript, is it permissible to use a function as a prototype, e.g.</p>
  
  <pre><code>function Foo(){
  
  }
  
  Foo.prototype = function(){
  
  }
  </code></pre>
  
  <p>or is it required to use</p>
  
  <pre><code>Foo.prototype = { };
  </code></pre>
  
  <p>and more importantly, does it make an important difference?</p>