MY MOBILE LOCKED AND I FORGET THE LOCK CODE - Nokia 5310 Cellular Phone

As you have not specified which code you need i am hereby giving how to get all of the codes:

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

PUK CODE:

PUK code can be given only by your service provider which is specific for each and every mobile number.
Contact your sim customer care department over phone. Its free of cost to get the pin or puk no. If you cant contact through your phone get some other phone and contact them.
Go to the nearest service outlet of your service provider they can also help you.
There is no other go than the above procedure only your service provider cangive it nobody else in this world nor any software.
Go to the below link and you can confirm that the above procedure works and there is a testimonial given by the customer too. http://www.fixya.com/support/t3582685-phome_lg_ke670_put_security_code_phone

PIN CODE:

HI If you are asking for pin contact your service provider , he will give you a default pin .

If you try pin more than few predefined no of times your phone will ask PUK code which can also be given only by your service provider which is specific for each and every mobile number . Do not try PUK(new pin code) code many times or else your sim will be blocked and you will need a new sim.

Contact your sim customer care department over phone. Its free of cost to get the pin or puk no.
Go to the nearest service outlet of your service provider they can also help you.
There is no other go than the above procedure only your service provider can give it nobody else in this world nor any software.

SECURITY CODE:

If it is lost nothing can be done. You need to flash your mobile at an authorised service centre which will reset the mobile memory and also all the data inside the mobile will be lost.