Help with managing Data and WiFi connections
 

I just started using my WM 6.1 phone with WiFi capability. I also have 75MB plan through Verizon from a long time ago.

I will not be using the browser or other data connection much, just to download email and occasional browsing when needed.

Is it possible to be to have the phone automatically use WiFi when at home (or public) and the phone data connection when WiFi is not available? if not automatically, what are the settings I should be manipulating to make sure I use WiFi and not Data when available?

Thanks so much for your help. I apologize to those of you who are true geeks; I'm a geek wanna be, but I'm afraid my question may be a bit stupid.