Library short story joke

A man enters a library and walks up to the librarian at the desk and says loudly, "I'd like a cheeseburger with fries, hold the ketchup!".

The librarian replies in whispered tones, "But sir, this is a library!".

Coming to his senses, the man replies in a whispered tone, "Can I please have a cheeseburger with fries, hold the ketchup."