Turn on wifi on a 4s I phone.?

[john]

I thought it was on when checked it wasn't but it won't let me slide the bar to the on position and the screen doesn't look like it used to seems like something is missing.

[Brandon]

If you're on iOS 7, you can drag up from the bottom of the screen to open command center and turn it on from there. If you haven't already done so, you can do a hard reset (by holding the power and home button at the same time until it shuts off and the apple logo comes on) which might help. Otherwise, the apple store can help you with that.