How to change the default thank you page with a custom URL?

Hello,

I would like to create a form when the submit button is click, the user is redirected to a url or a message is displayed. 

So far I've only been able to get the form to display the thank you page after submitting. 

Is it possible to set the conditions on the submit button?

You can not display a message when the submit button is clicked, however, you may change the URL of your thank you page and send your submitter to a custom thank you page with your own styles and message, this guide will help you to change the URL: http://www.jotform.com/help/38-Redirecting-Users-to-a-Different-Page. 

This guide could be helpful as well, it will help you to customize your thank you page: http://www.jotform.com/help/211-Setting-Up-the-Thank-You-Page.