I just purchased a refurbished HTC Eris for my teenager. I bought a prepaid phone plan through PagePlus Cellular and the phone plan operates on Verizon. The plan I bought provided a few Gs of data. My son told me that he watched one video on YouTube and went on FB twice. Well after that he could not access the internet. He was told that he had used up all his data- that is not acceptable. So I found out that Straight Talk offers unltd. data at cheaper price than what I would have to pay PagePlus but their SIM will only work on an unlocked phone. How do I know if this phone is unlocked. I do know it is CDMA and dual band Mhz whatever that means but the StraightTalk agent told me that as long as the phone is an unlocked phone the ST SIM will work. Can anybody help me with this please? i just don't need to lose more money.