How to block a number on iPhone 4S? - 1

I went to settings then phone but couldn't see a block option.

Http://www.google.com/webhp?nord=1#newwindow=1&nord=1&q=How+to+block+a+number+on+iPhone+4S&safe=off

Settings>Phone>Blocked>Add New

Probably not even possible.
they can send a man to the moon (not really, but.) and we can't block a number on a phone.
if it's really important, i know it's possible on samsung phones though.

If you have iOS 7 then its easy to block a number, otherwise you can't.