jailbreaking my iphone 3gs

[desha]

I was wondering about jailbreaking. I bought my iphone used and I don't know if it is already
jailbroken or not. How do you check to see if it is or not? I know it's unlocked or so I've been told.
I can send and receive calls and text messages, I can also get online, but I can't send or receive
mms. Any suggestions on how to check? Is it doable and is it safe?
Thanks!

[desha]

Hey, I'm just trying to figure out how to reply in a private message to some help. I think i read somewhere that you have to have at least 5 posts before you can. Is this true? thanks!