title: Coffeescript function is undefined
body: <p>I create a coffeescript function <code>square=(x)-&gt;alert x*x</code><br>
  It's compiled into this javascript  </p>
  
  <pre><code>(function() {
    var square;
  
    square = function(x) {
      return alert(x * x);
    };
  
  }).call(this);
  </code></pre>
  
  <p>So if i write this code  <code>&lt;button onclick="square(5)"&gt;</code> compiler says that <code>square()</code> is undefined. What's wrong?</p>