How to turn off DATA without turning off calls?

Hi,

This may seem like a really basic and dumb question.

How do I turn off my "data" to my carrier, but still be able to use my phone for calls?

I want to use my phone for phone calls as usual, and for connecting to the internet ONLY using WIFI when it's available. I don't want it to switch automatically to data mode via the carrier.

It should extend battery life and keep me under my monthly data limit.

Please don't laugh if this seems like a silly question - I honestly don't know if 3G JUST means the internet connection or it it means both internet AND phone or if it just means the phone.

I have a jailbroken 4S and NCsettings installed.

I have "Cellular Data" (little antenna symbol) and "3G" (3G symbol) as toggles - which one do I disable so that I can still make and take phone calls, but won't make my phone connect to the internet using the carrier's cellular connection? Or are they permanently linked?

I honestly don't know.

Is 3G just for the actual calls and Cell Data just for the Internet?

Which is which?

Or am I hopelessly confused? lol

Thanks.

Can I do that in NCsettings too? Or just SBsettings?

So - what do I turn off?

Do I turn off the 3G symbol? Or turn off the Antenna Symbol?

I just want to turn off cellular data and keep WIFI and Incomming/Outgoing Phone Calls running.

Which option should I toggle off?