To do this, first create your registration landing page and form and place the form on the landing page as you would normally. Then, add an HTML element to the page. In this element, we will add some code that activates at the moment the form is submitted. It will then hide the form and reveal a hidden <div> that contains the thank you message.
//Add an onSuccess handler
//get the form's jQuery element and hide it
document.getElementById('confirmform').style.visibility = 'visible';
//return false to prevent the submission handler from taking the lead to the follow up url.
<div id="confirmform" style="visibility:hidden;"><p><strong>Thank you. Check your email for details on your request.</strong.</p></div>
You will want to edit the two highlighted sections. The first should reference your Marketo instance (e.g. “//app-sj06.marketo.com/js/forms2/js/forms2.js”) and the second should contain the thank you text that you want to display once the form is completed.
The text will display on the landing page in the exact position where you place the HTML element, so be sure you edit that in the property sheet. You should also make sure the layer of your HTML element is smaller than the layer for your form. By default, both will be put at Layer 15, so you will be safe if you make your HTML element Layer 14. If you don’t do this, you won’t be able to type in any form field boxes that overlap with the thank you message.