Macbook pro 2011 i7 startup password problem

hi, i have some problem with my macbook, i do something with system files and now when i want startup mac , shows folder with ? , normaly i will startup from CD or external hdd, but some time ago i put firmware passwort on startup menu and forgetet
i try clean pram by 3times p+r+option+command with change of ram amount ,but laptop is 2011 and have new security
question is , did Nvram (pram) have any battery or its on eeprom chip ?, how i can remove that password?

i read i can go do apple store, but i dont know how much they charge mi ,but is there other way ?

Try inserting your Mac OS X reinstall DVD that came with your MacBook Pro. You do not want to install the OS, but instead you want to go up to the Utilities menu and click on Reset Password. Hope this helps.

That's not going to work to reset a "Firmware Password". As the OP mentioned he has a 2011 machine and that means new security.

To the OP:

Take your machine to your local Apple store and bring along proof of ownership of the machine. They'll reset it for you.