If you haven't changed the default security code that came with your phone when you first bought it, then you will probably find that it is still the same. If you don't know it then try looking through the paperwork or the instruction booklet that came with your phone when you bought it. Just spend a little bit of time flicking through the paperwork and using the index of the instruction booklet to find the security code section which could tell you more information about what to do in the event that you lock your phone.
If you did change your code and forgot it, or you cannot find the original default code, then you could try visiting the store that you bought the phone from. Everyone forgets there could at least once so these guys will be used to requests about unlock and there is a good chance that they will be able to help you. If not, then one thing they will be able to do is to point you in the direction of someone who can help you. If you are lucky, they might even be able to ring up someone for you to find out your code.
However, if this fails then give your network provider a call and explain the situation to them, including the make and model of your phone although they will probably ask you for this anyway if they don't already know it from your details. They have probably heard this problem a lot so will be used to getting these calls. They will give you a code that you will be asked to enter into your phone, following the instructions that they give you. It is a good idea to stay on the phone with them whilst you enter the code so they can check whether or not it works.
If you did change your code and forgot it, or you cannot find the original default code, then you could try visiting the store that you bought the phone from. Everyone forgets there could at least once so these guys will be used to requests about unlock and there is a good chance that they will be able to help you. If not, then one thing they will be able to do is to point you in the direction of someone who can help you. If you are lucky, they might even be able to ring up someone for you to find out your code.
However, if this fails then give your network provider a call and explain the situation to them, including the make and model of your phone although they will probably ask you for this anyway if they don't already know it from your details. They have probably heard this problem a lot so will be used to getting these calls. They will give you a code that you will be asked to enter into your phone, following the instructions that they give you. It is a good idea to stay on the phone with them whilst you enter the code so they can check whether or not it works.