Where is the billboard in wireless quest

Well, sometimes when I'm playing Wireless Quest, it's on (or in) the FIRST room you're in, BUT... it might NOT be in the room you're in, it could be, in the Maths/Science classes, near the library or any room. But, every time you play at different times, there are like 1-2-3 billboards in the building I think, but, in a random choice, so I suggest that you check every room until you've it.
PS
The billboard is not like those ones on the road, I mean, really, but, the billboard is like a..... well like a.... NOTICE BOARD, yeah a notice board now I just got that word.