Problem with Counter-Strike Source

[WeGotVlad]

I bought HL2 yesterday and am loving the single player mode. However, when I try to play CS Source I can load it and everything but when I want to change filters everything will change but the Games section. It is frozen and I can't do anything. I can change the Latency, map, anything else but I cannot choose a game I want to play. Anyone know why this is happening?