Cant turn on Wi-Fi on iPhone?

When i go into settings then wifi it doesnt let me switch it on, its like its blocked, i got it to work some how but i cant do it now, someone please help

Try rebooting it to reset any conflicts in your operating system's services.
You don't mention what kind of phone it is so I can't tell you how to reboot it.
Good luck.

I have a 4s and am having the same problem. Any suggestions?

It wont let me swipe the button its like frozen i need so help