LG

I hope someone can help me, because at&t doesn't seem to have a clue! I am trying to access the Mmode service on my phone & it will start connecting, but then says "network error". The only information I can find in the phone's handbook says that I need to indicate my phone number via the own number menu option. I tried to do that, & it is asking me to enter a "pin 2"...for some reason customer service is clueless on what the pin 2 is.....any suggestions???