title: Alias function in javascript
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/8773579/if-javascript-has-first-class-functions-why-doesnt-this-work">If Javascript has first-class functions, why doesn’t this work?</a>  </p>
  </blockquote>
  
  
  
  <p>When I try to make an alias function for <code>document.getElementById</code> as below:</p>
  
  <pre><code>f = document.getElementById;
  </code></pre>
  
  <p>But, when I try to call:</p>
  
  <pre><code>var e_fullname = f(“fullname”);
  </code></pre>
  
  <p>It was rised an error:  <code>Could not convert JavaScript argument</code></p>
  
  <p>And below is OK:</p>
  
  <pre><code>var e_fullname = f.call(document, “funname”);
  </code></pre>
  
  <p>Can you tell me why?</p>