Unlocking Nokia 6103b

my IMEI is 359371002225474
but i read it in the battery compartment as 359371/00/2225474
so when I entered the number I used the slashes, it entered it as
IMEI: 359371/00/22254

and skipped the last two digits because I used slashes. i tried again to enter the code as 359371002225474 with out the / / but it said I already had a code attempted, and it only allows one free code.

so how can I find the unlock code for 359371002225474

I tried one of the bad numbers already, but only once so I should have a couple more tries

or if anyone knows the code I can use that'd be great. :confused:

also do I need a SIM in the phone or does it have to be empty