title: Validate combined normal form with dropzone
body: <p>How can I validate input fields (email, username) before submit form with file upload?
  it's possible integrate jquery validation plugin inside dropzone?</p>
  
  <pre><code>&lt;form id="my-awesome-dropzone" class="dropzone"&gt;
   &lt;div class="dropzone-previews"&gt;&lt;/div&gt;
  
    &lt;!-- Now setup your input fields --&gt;
    &lt;input type="email" id="email" name="email" /&gt;
    &lt;input type="text" id="username" name="usename" /&gt;
  
    &lt;button type="submit"&gt;Submit data and files!&lt;/button&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>javascript dropzone file</p>
  
  <pre><code>Dropzone.options.myAwesomeDropzone = { 
  
  // The configuration we've talked about above
  autoProcessQueue: false,
  uploadMultiple: true,
  parallelUploads: 100,
  maxFiles: 100,
  
  // The setting up of the dropzone
  init: function() {
  var myDropzone = this;
  
  // First change the button to actually tell Dropzone to process the queue.
  this.element.querySelector("button[type=submit]").addEventListener("click", function(e) {
      //I wont to put validation plugin here:
  
     $('#my-awesome-dropzone').validate({
       rules: {
          email: {
              required: true
          },
          usename: {
              required: true
          }
       }
    });
  
    e.preventDefault();
    e.stopPropagation();
    myDropzone.processQueue();
  });
  
  //...
  </code></pre>