<form id="form-add-dataset" role="form" action="submit.php" enctype="multipart/form-data" method="POST" >
    ...
    <input type="url" name="authors_website" class="form-control" autofocus>
    ...
    <button id="upload-button" type="submit" class="btn btn-lg btn-primary"><span class="glyphicon glyphicon-upload"></span> Upload</button></div>
</form>

$("#form-add-dataset").submit(function() {
    //Do stuff
});

$('#upload-button').on('click', function(){
  if(){ // test your params
   return false;
  }
  return true;
});