I have a nokia n70 which is locked to orange but want to use with my 02 sim

NETWORK UNLOCK CODE:

You can unlock it by flashing your mobile if your mobile is a CDMA mobile...
The procedure for flashing your mobile is in the link below
http://hubpages.com/hub/How-to-Flash-your-cell-phone
It has an video explanation.

If your mobile is not an CDMA mobile , you can get the network unlock code(NUC) by just contacting the current network provider customer caredepartment.It is free of cost.

Therestrictioncodecan be got from your old service provider..This restriction code iskeptto prevent someone who stole themobile from using it withanotherprovider...

They will have a security check done with your date of birth etc..to verify whether you are the exact owner of the phone..

After that they will provide you the restriction code to unlock it and use it with another service provider..

It is all free of cost donot pay anyone for this seeing some advertisement over internet . That is all fake ads.

The above proceudre works and you can verify that by seeing the rating of an happy customer here..
http://www.fixya.com/support/t4035818-need_unlock_nokia5130c_2_use