Hi guys
 
your child does something stupid on the phone??
Well here is a solution by adding a phone lock
First of all there are 2 types of nokia phone (according to me)  that is symbian
And Java
Symbian
For symbian it is very easy
just press your switch of button once and see down
There will be a button called phone lock it will ask u code press 12345 or 1234
It is the default code
To change it go to settings security settings and phone lock and change the code!
Java
Go to setting phone settings key guard  settings and set the keyguard code and automatic key guard on
The default code is again 12345 u can change it too by
going to security settings-> change access codes -> change security code
Thanku !