Can't Protect Form

[SWFisherman]

I have made a document in word with form fields and after I finished making
it I went to protect the document allowing editing only for filling in forms
but for some reason the "Yes, Start Enforcing Protection" button stays gray.

I made this document from another one that is very similar and pretty muched
just added a few checkboxes and changed the wording around. Any Ideas?

 

[SWFisherman]

Nevermind, I had it in design mode. Just one click of the button did it.