title: jQuery addClass in external js file issue
body: <p>Here is my code:</p>
  
  <pre><code>&lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head runat="server"&gt;
      &lt;title&gt;&lt;/title&gt;
      &lt;script src="scripts/jquery-1.10.1.js"&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;link href="css/colorcss.css" rel="stylesheet" /&gt;
      &lt;script type="text/javascript" src="scripts/sample.js"&gt;&lt;/script&gt;
      &lt;form id="form1" runat="server"&gt;
      &lt;div&gt;
          &lt;input type="button" id="btnSample" value="click me" /&gt;
          &lt;label id="lblAll"&gt;All Toggle&lt;/label&gt;
      &lt;/div&gt;
      &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p><strong>javascript:</strong></p>
  
  <pre><code>$(document).ready(function () {
      $("#lblAll").addClass("defaultColor");
  });
  
  $("body").on("click", "#lblAll", function () {
      $("#lblAll").toggleClass("dummy");
  });
  </code></pre>
  
  <p>css:</p>
  
  <pre><code>.dummy {
       background: yellow;
  }
  .defaultColor {
  background-color: aliceblue;
   }
  </code></pre>
  
  <p>The question is, the above code is not working. I'm trying to use addClass where the js is written in some external js file. Same script, if I put under the body it works fine. Am I doing anything wrong?</p>