quastion about my unlock droid razr hd

[fire159]

hi all dear ultra user .

i buy one droid razr hd from ebay .
its gsm unlock ( i dont know its factory unlock or unlock with code )

and i use it very good .

if i flash new rom or update it . is this possible my phone do lock carrier after update or flash new rom ?
but i afried to update my phone and Lose it unlock .


please answer if you know ):
sorry for my bad english