I would caution about screaming at a gate agent. If anyone has watched A&E's "Airline", you will know from a couple episodes that ticketed passengers have been denied boarding and even removed from the aircraft for shouting, swearing at, and screaming at the gate agents. I would probably not scream at an agent, but if they royally screwed up and the blame did fall on them or the airline, I may demand some resolution, solution, or answer in a stern, and firm voice, not wanting to cause them to call airport security or police! Sometimes being so nice and pleasant on our part might get you somewhere. I know some thing that's crazy, but I've seen it work. A sense of humor gets you a lot farther than screaming in my book. The gate agents have a demanding job, deal with a ba-zillion different issues daily (late arriving aircraft, mechanical problems, weather, no crew to fly the aircraft, etc....) that are out of their control. But, when they have screwed up, there is no excuse. I can not tolelate their incompentance, especially when they don't or won't go find an answer. I learned long ago when I was in retail management that if you don't know the answer let the customer know you don't know but you're going to get an answer, then move your butt to get that answer and get back to you customer. That'll win them over big time! So folks, no screaming! Save it for the ball games!