. >> jeff maddox with the fire control and you can hear me through the microphone okay? >> yes. >> i would like to see the results of the studies we have also been doing studying various ducted systems with our cfd analysis, and for the buildings that are under construction and design and i am curious to see how there are results compared with this corridor air scheme. and so i would... and one of the things that i would like to think about though, is john, you mentioned that if air or smoke has moved into the corridor and the egress problem? and i think that we could use a study to evaluate just how much smoke it takes to make that corridor untenantable and is that something that is included in your study so far. >> yes. >> i think that is a big part of it to figure out if there is an opening where the damper fails, how much time there is in the corridor, for the rest of the tenants to respond and get out. >> the idea that there is be no smoke in the corridor is a very conservative and how long they can be in the space, and that is really where we need to go. and i do w