Siemens SL55 Asks for "network Lock" plz help a.s.a.p

[the_frightener]

hola folks !

Siemens SL55 shows "network lock" when simcard inserted

some 1 plz give me the unlock codes for this ...

imei is :351630001744803
network: orange u.k

plz help me a.s.a.p

Big thanx in adv