Validation and Impromptu plugins

Validation and Impromptu plugins

I'm using jQuery Validation plugin for a upload form, and while the file it is uploaded i must display a message, so i have choosed Impromtu plugin to do this.

The validation code for the form is:
<script type="text/javascript">
$().ready(function() {
   $("#form_upload").validate({
      rules: {
         file_artist: "required",
         file_title: "required",
         file_upload: "required",
         category: "required",
         subcategory: "required"
      },//rules
      messages: {
         file_artist: " - Please enter the artist!",
         file_title: " - Please enter the title!",
         file_upload: " - Please select a file to upload!",
         category: " - Please select a category for the song!",
         subcategory: " - Please select a sub-category for the song!"
      }//messages
   }); //form validate
}); //function
</script>


And the message box code is attached to the submit button:
<input class="submit" type="submit" name="upload_now" value="Upload File" onclick="$.prompt('Uploading, please wait...');" />


Both scripts are working great. But i would like that "Uploading..." notice to apear only if the validation is ok, because now it shows even if the required fields are blank.

I guess that i must use SubmitHandler in Validation script, but it beats be how.

For the last 4 hours i have searched some ways, but i simply don't understand javascript, so please give me a hand.