HOW DO U REGIISTER AT THE SIMS 2 WEBSITE!! i dont get it?

when i click on register or creat new user it brings something up that says choose your plat form and i try to choose pc and mac but then it just clears it off the line then under it.. it says choose a game and i dont get it because it wont let me pick a game... am i in the right thing! can someone please give me directions for the sims 2 register thing and if u can make me 1 i would be so0o0oo happy.....