I forgot my cell's security code. what to do now?

Power off the phone.
Press and hold Green, * and 3.
Keep them held while Phone is powering on and for a few seconds after that.
It will Format your phone compleatly and bring it back to the Factory Setting.(But the data which is on memory card will not delete)

It will clear all the Codes or Passwords.

I am sure this is going to work.

I cannot lock my keypad of 3500c whenever i try 2 put security it show me code error