title: Cq5 building a number increment/decrement box
body: <p><img src="https://i.stack.imgur.com/EflkZ.png" alt="enter image description here"></p>
  
  <p>the above picture is what i need to build in CQ5, I　have been digging around in <a href="http://dev.day.com/docs/en/cq/current/widgets-api/index.html?class=CQ.WCM" rel="nofollow noreferrer">adobe cq api</a>,
  all i have found is <code>Class CQ.Ext.form.NumberField</code></p>
  
  <p>but that number field only provide something like textfield for you to manually entering number(this is not what i need)</p>
  
  <p>can anyone guide me how to create such number increment/decrement box in cq5 dialog? with some code example please, thanks</p>