title: Form in Zend not submitting with <button> submit type only submits with <input>
body: <p>I'm updating a form in my zend project it's pretty basic. After updating the form to use a <code>&lt;button type="submit"&gt;</code> tag it's not posting the form.</p>
  
  <p>Does not work
  <code>&lt;button type="submit" name="Save"&gt;Continue&lt;/button&gt;</code></p>
  
  <p>Works <code>&lt;input type="submit" name="Save" value="Next"&gt;</code></p>
  
  <p>Part of the code in the controller which throws  the error is below, why is <code>$value = trim($value);</code> showing up empty when I post the form? All my fields and form action is correct I've tested everything and it's come down to the submit button type being the problem. Thanks</p>
  
  <pre><code>    $userSess = new Zend_Session_Namespace('Default');
      if (!$this-&gt;getRequest()-&gt;isPost()) {
      $this-&gt;_helper-&gt;redirector('index','welcome');
  }
  $postData = $this-&gt;_request-&gt;getPost();
  //validating form data, if empty data comes, redirect with err msg
      foreach($postData as $key =&gt; $value) {
          $value = trim($value);
          if($value == "") //if empty field submitted, redirect back with invalid msg
          $this-&gt;_helper-&gt;redirector('index','welcome',null,array('err'=&gt;'Please Fill in all details'));
      }
  </code></pre>