I have a Sony Ericsson phone that is an unlocked GSM phone that I got overseas. If I purchase a T-mobile SIM card with a pre-paid plan through T-mobile, will the SIM card work on that phone or does it have to be only T-mobile? (http://www.t-mobile.com/shop/phones/Detail.aspx?class=prepaid&device=53299206-c069-429a-82fa-000007a2ac12)