[Plugin: Visual Form Builder] Customising the success message

What a fantastic plug-in, thanks so much Matthew!

I’ve been struggling with trying to customise the success message for a few days now. (‘Your form was successfully submitted. Thank you for contacting us.’) I’ve had a look through all of the Support threads, the API Documentation and the StackOverflow topic, with no luck so far.

I’m guessing the solution for changing the default error message is on the right track (http://wordpress.org/support/topic/visual-form-builder-localization-problem?replies=8#post-2296212), but I haven’t managed to get it to work yet.

Can I use this solution, and if so what should the key be (to replace required/email)? :

jQuery(document).ready(function($) {
	$.extend($.validator.messages, {
		required: "Eingabe nötig",
		email: "Bitte eine gültige E-Mail-Adresse eingeben"
	});
});

Any help would be much appreciated.

http://wordpress.org/extend/plugins/visual-form-builder/