Jail Breaking Iphone 3gs

I have an Iphone 3gs, and I'm trying to jailbreak it. I'm using the Redsn0w thing to do it. But when I get to the last step of jailbreaking it, it says "The connected device doesn't support unethered options" How can I fix this? Or better question, what is a better way to jailbreak it?

My motto when it comes to jailbreaking.
if you can't figure things out yourself, you shouldn't be jailbreaking.