title: load jQuery in another js file
body: <p>I have a JavaScript file, which also uses jQuery in it too. To load it, I wrote this code:</p>
  
  <pre><code>function include(filename)
  {
      var head = document.getElementsByTagName('head')[0];
      var script = document.createElement('script');
      script.src = filename;
      script.type = 'text/javascript';
      head.appendChild(script)
  }
  
  include('http://ajax.googleapis.com/ajax/libs/jquery/1.7.0/jquery.min.js');
  alert("1");
  
  $(document).read(function(){});
  alert("2");
  </code></pre>
  
  <p>This fires <code>alert("1")</code>, but the second <code>alert</code> doesn't work. When I inspect elements, I see an error which says that <code>$</code> in not defined.</p>
  
  <p>How should I solve this problem?</p>