I am creating a library kinda application in SharePoint2010 and i am truck up with a scenario.
I have a List A,where the book names and their details are updated with the availability(Total no. Of books available).
For the users requesting for books from library,i have created another List B and the book title from List A is added as a lookup field in List B.
Now, for instance there are only 2 books titled “Book1”. If both the books have been taken by 2 different users, when a 3rd user who requests for the same book(Book1) should not be able to make the request through List B.May be a error message shall be displayed.
If any other approach would work for my requirement, that would also help.
The main requirement is that if the available stock of books are already over/taken, the next user should not be able to make the request.