T-Mobile branded phone

I bought a T- Moblie Brand Motorola V3 cell on ebay the phone works great . Today i tryed to get access to the web. I some how in the internet setting on the phone choose Java where its says home. and the rep from ATT says it needs to say media net there inorder for it to go to the web. I don't remember how to change that. i remember chooseing it from a list but can't find anymore. any ideas on how to change the setting to media net