title: Find input class in DOM using javascript
body: <p>Hi I'm using CEFsharp to automate through a website and fill in fields etc.. As so far I have not been able to get jquery working i'm using javascript and have come across a problem.</p>
  
  <p>When I try to find an input field:</p>
  
  <pre><code>&lt;input class="quantity" type="text" value="1" maxlength="2" size="2" name="quantity"&gt;
  </code></pre>
  
  <p>I use javascript:</p>
  
  <pre><code>document.getElementsByClassName('quantity')[0].value = '3';
  </code></pre>
  
  <p>This works fine the first time and 3 items are added to the basket.
  However once items are in the basket a span class is created so the array placement of the class quantity is no longer 0 and so does not find the input class that I am looking for.</p>
  
  <pre><code>&lt;strong class="quantity"&gt;3&lt;/strong&gt;
  </code></pre>
  
  <p>I know in jquery this would be easy but for the time being i have to use javascript so what is the javascript equivalent of doing:</p>
  
  <pre><code>jquery $('input.classname')
  </code></pre>
  
  <p>Thanks!</p>