I just got my kitty a few months age and I have people telling my that it's a girl and I have people telling me that it's a boy. I think it might have balls but their really tiny and its too hairy to see if the hole is round or a slit. It sticks its but in the air when I pet it. I really need to know because I don't know what to name it.

Apparently, your not alone. A quick search yielded this site:

What Is The Sex Of My Kitten? Learn Here At ThePetCenter.com. (http://www.thepetcenter.com/exa/kitx.html)

So do I I think it's a boy but mine is bigger and harry

Try this, Wet a Kleenex or something like, and wet the area in question so that the hair will stay out of the way. If you still can't tell whether a slit or just round, put pressure on either side of the opening, top/bottom or side/side, no matter. Then see if anything peeks out when you push inwards. If so, you should have your answer. If not, you ought to better be able to tell if it's a slit or not, then.