How do i get new weapons on battlefield 2?

I just became a private first class on batllefield 2 for the pc. how do i unlock new weapons?How do i get new weapons on battlefield 2?
Keep playin...the more people you kill and the longer you play the better weapons you'll get...Basically your world score has to go up the more you play...its really gay...cuz everyone can kill you with like 1 shot before you can kill them with 8 shots. Goodluck man...dont get addicted. Also, playing on the same maps constantly will unlock weapons for that map faster...cuz weapons unlock by map.How do i get new weapons on battlefield 2?
Just keep beating levels like the other guy said and you'll have all the weapons in like 4 days depending on how much time you play and how long it takes you to beat each level...