Why can't I get Wi-Fi at school on my iPhone 4?

All my friends can get internet in school, whereas I can only get it at home! It's annoying and I just wondered if I needed to do something to get it? I asked my friends how they did and they said it was always just there! I only use it in school when I have free periods, or at lunch etc so I just get a bit bored without it.

Do you have data plan enabled on it? And if you do, you don't have Wi-Fi there because you will need reception for it, the reason why you wouldn't have reception is because your in a building. Some buildings won't have reception in them.