Ghostbusters: The Video Game Achievements

Can someone tell me which office they are talking about for this achievement?  I can't seem to find it. 

You're gonna enter a building while Stay Puft follows you around Times Square. You're gonna be going to the top of the building and you'll eventually enter a large room where you have to fight a large horde of marshmellow creatures.  After finishing off all the enemies, trash EVERYTHING in the room.

There's also an artifact in the corner by a window.

@Android22: ahh ok thanks! it's no wonder I couldn't find it, i didn't even try to until after that level :P

im in the room doing wha u said and it hasnt gave it to me yet

You have to move on the next room before you get the achievement, so make sure you blow up everything, all the glass, furniture, decorations, things on the walls, etc, that you can, then talk to dan akroyd.  Then you will get the achievement.

What I did was I destroyed everything until nothing was earning me damage money.  In the top left corner of the screen, where you see how much money in damages you've totalled, I made sure that no matter where I sprayed my proton pack there was no more money being earned.  I literally went apeshit in there and destroyed everything.

@Out_On_Bail: Its the room where the marshmellow bits come through the ceiling when you use your PKE meter the achievement won't activate until you leave the room so make sure you destroy EVERYTHING.

@ZenGaijin:
so u do u know how to get the ive quit better jobs than this