I'm kind of new to PC gaming - in fact, my very first online game was last night. I know there is a way to text chat while in-game. For Left 4 Dead, I'm told it's either the Y button or the U button, but when I press said button nothing is coming up so that I can type or even to say that anything I typed was sent out. Is there anything additional I'm supposed to do? I've searched all over Google and I'm not getting an answer past "press Y or U".