title: How to add a property in existing css class using javascript?
body: <p>I want to add a css property in a class using JavaScript.</p>
  
  <p>Example</p>
  
  <pre><code>&lt;style type="text/css"&gt;
  .AClass{
     color:#ccc;
     padding:5px;   
  }
  &lt;/style&gt;
  </code></pre>
  
  <p>I want add a property height:500px; in this class using javascript, not on that element which class is AClass. So finally my class should be</p>
  
  <pre><code> &lt;style type="text/css"&gt;
      .AClass{
         color:#ccc;
         padding:5px;   
         height:500px;
      }
      &lt;/style&gt;
  </code></pre>
  
  <p>But programmatically.</p>
  
  <p>Please Advice me</p>