When i tried to use internet it is showing data connection unavialable?
Check your Internet settings. Do you already have the correct configuration in your phone? If you don't have yet, just contact your carrier so they can either assist you to do the setup step-by-step or they can just send you the settings and you just have to save it. Also see if you have good reception when connecting to the Internet. A weak reception can hinder you from connecting to the Internet on your mobile phone.