title: How to increase the value of text field on page load in JavaScript?
body: <p>I want to increase the value of text field on page load in JavaScript.
  For example</p>
  
  <pre><code>&lt;input type="text" name="itemquantity[]" value="1"/&gt;
  </code></pre>
  
  <p>after pageload it shoud be  like</p>
  
  <pre><code>&lt;input type="text" name="itemquantity[]" value="2"/&gt;
  </code></pre>