title: How to get custom attribute value in jquery or JS from radio buttons?
body: <p>I got a piece of HTML:</p>
  
  <pre><code>&lt;input type="radio" name="radioBtn" onChange="rdbtn()" value="100" isprm="true"&gt;
  &lt;input type="radio" name="radioBtn" onChange="rdbtn()" value="110" isprm="true"&gt;
  </code></pre>
  
  <p>and I want to pass the custom attribute value into a variable. Here is what I tried and does not work:</p>
  
  <pre><code>function rdbtn(){
     var radioVal = $(this).val();
     var radioPRM = $("input[id=radioVal]:checked").attr('isprm');
     ...
  }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>$('input[id=radioVal]').data("isprm");
  </code></pre>
  
  <p>No luck. Do you have any ideas how to make it work? Thanks.</p>