i do not see a comments field anywhere in your hierarchy.
to get the right text box you can your a "ctrl" shortcut
when you are in the code window for your checkbox (make sure the cursor is active in the code area i.e. the little line is blinking)
then hold ctrl and click on the text field you want to use
(when you hold ctrl the cursor will turn into a little triangle thing)
hope i didn't confuse you.