title: How to validate if textbox value is empty in a series of textboxes?
body: <p>There are a series of textboxes like:</p>
  
  <pre><code> &lt;input  type="text" class="jq-textBox" /&gt;
   &lt;input  type="text" class="jq-textBox" /&gt;
   &lt;input  type="text" class="jq-textBox" /&gt;
   &lt;input  type="text" class="jq-textBox" /&gt;
   &lt;input  type="text" class="jq-textBox" /&gt;
  </code></pre>
  
  <p>User can fill up the textbox values from top to bottom order. Only first textbox is required and all other textboxes are optional.</p>
  
  <p>Allowed order to fill textbox values:</p>
  
  <pre><code>1st
  1st &amp; 2nd
  1st, 2nd &amp; 3rd
  and likewise in sequence order
  </code></pre>
  
  <p>Dis-allowed order:</p>
  
  <pre><code>2nd
  1st &amp; 3rd
  1st, 2nd &amp; 4th    
  </code></pre>
  
  <p>This means that user needs to fill up the first textbox only or can fill up the other textboxes in sequential order. User can NOT skip one textbox and then fillup the next one.</p>
  
  <p>How to validate this in javascript/jQuery?</p>
  
  <p>Any help is highly appreciated!</p>