Have no internet connection

We bought an htc Inspire a few days ago. My daughter had to take a trip out of state and now she has no internet connection. HELP please!

NEVER take out the battery on your phone when it is on.  That is how you corrupt files.  Only remove the battery as a last resort like when the phone is totally locked up. 

Wrong info. And it can cause data corruption.   You pull your battery out AFTER the phone is correctly powered down.

Reset your connection in your settings  if you have these settings.

settings > wireless & networks > mobile networks > neywork operators > network operators        and allow the phone to find the operator.   When it finds it then select it and it will return registered on the network.  If you have more than 1 network in range then select "Select automatically"  and select the preferred data connection.

I believe that is correct.  The APN's are different for the 3G and 4G plans if I am not mistaken.

Dunno, ATT might have it locked to only them.  So it could be because of sim lock or the ROM.  My phone is unlocked and has an unbranded ROM.

I went to ATT yesterday and had my phone and sim card switched out.  (mainly cause I dropped my phone and tohught maybe that jostled the antenna...) They tried to tell me that with 4g it will fluctuate seeing it is a newer network, but even with low bars reception should be good seeign it is stronger.  The so-called 4g network is not available all over, so it will change to 3g and E when nothing else is available.  That is what mine was doing, however since switching out, it is much improved and even stays on the H+ setting even in my office where I was not getting reception at all. 

My wife also began to have similar issues with her IPhone a week ago or so.  I believe the ATT network is just weaker all around.  My Verizon Droid 2 has full bars everywhere I go.