Where is Moaning Mrytle's bathroom?

[michaelkgidlow]

No: HPFGUIDX 71157

I posted on this yesterday, but new evidence has been brought to 
light. At the Deathday party, Hermione says that Moaning Mrytle's 
bathroom is on the first floor. When Harry hears the Basilisk, they 
go to the second floor where they find the writting which is next to 
Moaning Mrytle's bathroom. But then when Harry and Ron hide Crabbe 
and Goyle in the closet in the entrance hall (which is on the ground 
floor) they go up the staircase to the first floor and then go into 
the bathroom (this isn't specifically stated, but it is implied that 
they only go up one staircase). Then, When they lead Lockhart from 
his office (on the third floor), they lead him down one floor to the 
bathroom. So, is Moaning Mrytle's bathroom on the first or second 
floor?

Michael Gidlow