Default Lg optimus g pro imei reset

hello

i am from india i have unlocked lg optimus g pro at&t e980 i used it for 3 month without any problem but from today morning my iemi saw "0" and i am not able to make fon call or data use
how to reset iemi no pls help me asap

sorry for my bad english

i am not able to Access the phone's hidden menu using the phone keypad (dialer), enter: 1809#*999# ( i dial this number but nothing happen)
for reseting iemi as in link below

http://forum.xda-developers.com/show....php?t=1942417

MY IMEI IS RESTORED N I DO IT WITH IN 1HOUR AFTER START THIS THREAD
SORRY