How to get all hidden elements from a form using php

I always had problem getting all the hidden elements of a form when using cURL. So thought of making a function that extracts all the hidden elements from a form when passed as a string.
Here's the function

  function getHidden($form) {
     $hiddenElements="";
     $doc=new DOMDocument();
     $doc->loadHTML($form);
     $xpath=new DOMXPath($doc);

     //use xPATH for quering the hidden elements in a form passes as string $form
     $qry="//input[@type='hidden']";
     $xData=$xpath->query($qry);

     //loop thru all the data
     foreach($xData as $value) {
         //typecast the name and values as string to avoid xml object
         $eleName=(string) $value->getAttribute('name');
         $eleValue=(string) $value->getAttribute('value');
         $hiddenElements[$eleName]=$eleValue;
     }
     return $hiddenElements;
  }

?>

And thats it. The above function can be useful while doing a cURL using php to get form fields. Hope this helps someone