Stuck on SSH1 level

Xbox Forum

I got out of the elevator, knocked out the guard in the locker room, guard in the camera room, and both guards patrolling the hallway. When I go to enter the next room where they are having the meeting in the room w/ the big glass windows, there is a guard standing guard that I can't get past. There are 2 doors to enter. Either door I enter, he sees me and the men inside having the meeting see me. Can anyone help? Thanks.