Wordpress Contact Form Keyword

It seems that all forms do not have any thank you page set. Once you submit a form, it appears only the sentence that thanks. All forms we want to track should have a thank you page; better if the same (same unique URL)

- Create two ghost/hidden fields in all the forms of all the websites to catch the keyword (from PPC) and the G-Clid (from PPC). If needed, I’ll send to the developer more specs