I want MMS without my iphone trying to access the internet at the same time, and charging me for it!

Hi all!

I want MMS without my iphone trying to access the internet at the same time, and charging me for it!

Is there any way to block data access in my iphone without blocking MMS? I do not want nor need internet access on the iphone, but I do want to send MMS. But if I don't block data access, the phone keeps trying to access the internet and charges me for it. Checking for updates, some say. Then why is it that the iphone doesn't update when i'm on wi-fi?

One solution would be to make the iphone access the internet ONLY through wifi, and never with 3G and GSM. Is it possible?

Thanks all.