Add a text field below an X mark in pdf form

[Kevin Molloy]

Is it possible to automatically bring up a text field directly below an X when it's marked on a pdf form. I want to be able to mark an area on a diagram but give the user the option of adding a description below the X mark. 

[try67]

You can use a dynamic stamp for that, but they'll only be able to enter the text for the field at the they apply it, not later on.