How to block a contact with iphone 5?

I started using an iphone5 recently, n there was somebody with always call me but i didnt really want to pick it up. I know there was a do not disturb function in the phone, but all i want is to block that person's call, it is really annoying so please help me!

I think you can do that through your service provider, but there is an easier alternative. If you have a jailbroken device you can download an app called blacklist which you can block both calls and/or sms from a number.