Show region if a specific record not found in specific recordest

let, i have a site which contains articles users can register in my let, i have a site which contains articles users can register in my site & can open his "My Favorite Articles Box". Now when user login and surf my site a button is added on every article page.Button is "add this article to my favorite Articles Box". Their Are three tables in my site 1:-Login info 2:-Articles data 3:-User Favorite Articles data if user click on "add this article to my favorite Articles Box" button article name ,id,& link is added to "User Favorite Articles data" table but i want that if a user has added a article in his box the "add this article to my favorite Articles Box" button not show,& instead this the webpage show "this article has been added to your Box" Mean,i want to know that how to "show region(show button) if specific record (specific article) not found in specific record (User Favorite Articles data Table). Please help me i am waiting for reply.