[xwiki-users] Prevent delete some page

Hello, In my xwiki application, I want prevent user to delete pages (even he is the creator). Users create page with my form (some class/Sheet/Template/Velocity/API xwiki) and of course I want to keep original UserCreator info in the doc. Is it possible? I didn't manage with right access (XWiki.XWikiRights object). thxs Pascal B