Is it possible to place an X above the iframe embedded form to close it?

By the way, is there a way to add a 'X' to the thank you page so it can be dismissed?

This would not be possible to do within the form itself. You would need to add a new element above the form itself in order to be able to achieve this.

To do this, please add this HTML code right above the iframe:

<span style="float: right" onDISABLEDclick="document.getElementById('JotFormIFrame').style.display = 'none'; this.style.display = 'none';">X</span>

What will happen is that once you click on the x - it will hide both the x and the form.

Do check it out how it works and if that is what you wanted to achieve.