here are codes to enter the nck code
LG C3100 press 2945#*3101#
LG C3380 press 2945#*7101#
LG F2300 press 2945#*7101#
LG KE260 press 2945#*2601#
LG KE970 press 2945#*9701#
LG KG120 press 2945#*1201#
LG KG220 press 2945#*1201#
LG KG240 press 2945#*3311#
LG KG280 press 2945#*7101#
LG KG290 press 2945#*7101#
LG KG800 press 2945#*7101#
LG KU250 press 2945#*250#
LG KU380 press 2945#*380#
U310- 815118#*# and enter NCK