unlocking phone question....?

[Sdfsd Sdf]

ok so i just bought a cell nokia c3...ive never unlocked a phone...but i want to unlock it so it will be my first time....so what im curious to know is i found numerous websites that ask u to fill a form asking you IMEI number and they email you the unlock code. My question is, is it safe to give IMEI number? i dont know what it is so is it some personal number like serial code that no1 shud know?>
1 more question is ive spent 40 minutes i cant find anywhere how to raise the speaker volume..

[vicecaptain]

IMEI number is the unique identity number for your mobile phone. IT is not advisable to share your IMEI number to all unknown websites. Certain people say that they offer free unlock codes and misuse the IMEI number. So share your IMEI number to only reliable unlocking sites like Superunlockcodes.Com This site provides unlock codes at affordable cost with easy unlocking instructions.
You can't raise the default speaker volume limit which was provided on your mobile phone. If you are not getting the default speaker volume also, You can take it to any mobile service center.