Corrected entry: On page 105, Harry finds Mrs Norris petrified on the second floor. When Dumbledore asks them all to follow him, Lockhart tells Dumbledore to use his office, and he says that it's just upstairs, which would mean Lockhart's office is on the third floor. But on pages 91-92 it says that Harry is dragging his feet along the second-floor corridor to Lockhart's office for his detention.
Issabee
14th May 2006
Correction: Just because he was 'dragging his feet along the second floor corridor' does not mean Lockhart's office is there. he could have gone up a flight of stairs to reach Lockhart's office.