Custom admin page with mysql?

Hello!

I’ve made a custom admin page where I’ll would to put in some text and save it in my DB. I am using mysql to do a query to save it in the DB. But I am getting an error all the time when I trie to set the link to ?status=ok on the page I am. It says that I don’t have permissions to be here. What should I do? How can I do the query cross two files? Like on file where the query are submitted?

Best regards,
Joakim