Wifi or tmobile data network?

[wassup]

I'm still waiting for my tmobile mda to arrive and I have some questions about it. When your using aim or other instant chatting programs, how do you know if their connection is through wifi instead of the expensive tmobile data network? Does the internet explorer use the data network or wifi? I'm just want to know so I avoid getting a 200 page bill from tmobile. Thanks

[happytytn2user]

good question, because t mobile default program it to connect through thier expensive network. i removed my t mobile settings and set up my router with a wep key to allow my mda to the net.

if you need more help please let me know