title: how to post only user selected values in a form
body: <p>I have a form with 6 <code>&lt;select&gt;</code> options. All <code>&lt;select&gt;</code> filed will have same values but with different names. 
  Like this:</p>
  
  <pre><code>&lt;form action="" method="post"&gt;
      &lt;select name="var1" class="form-control"&gt;
       &lt;option value="0"&gt;0&lt;/option&gt;
       &lt;option value="10"&gt;10&lt;/option&gt;
       &lt;option value="20"&gt;20&lt;/option&gt;
       &lt;option value="50"&gt;50&lt;/option&gt;
       &lt;option value="100"&gt;100&lt;/option&gt;
       &lt;/select&gt;
  
      &lt;select name="var2" class="form-control"&gt;
           &lt;option value="0"&gt;0&lt;/option&gt;
           &lt;option value="10"&gt;10&lt;/option&gt;
           &lt;option value="20"&gt;20&lt;/option&gt;
           &lt;option value="50"&gt;50&lt;/option&gt;
           &lt;option value="100"&gt;100&lt;/option&gt;
      &lt;/select&gt;
      &lt;input type="submit" name="submit" value="Submit"/&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I am submitting these information to the same page, But before submit is it possible to filter those variables which are greater than 0? I want to <code>POST</code> only those variables which has value greater than 0. How can i do it?</p>