Just bought a Galaxy s3 from Ebay (I know, risky) and everything looks good so far. I am using this phone with the Straight Talk plan. Bought the Straight Talk sim card from Ebay. Now I have talk and text it's time for internet. When I go to change the APN I follow the instructions and have no problem getting to the correct screen. I click on menu and add APN. When the new screen comes up for the new APN I cannot seem to enter any information. I don't know if something is locked. I really don't know this phone at all. Has anyone had what I'm sure is a very simple problem. Thanks.