iPhone 4 can't detect any wifi

My school has 2 options for WiFi one with a password the other has no security because it's for guests.

All week my iPod has been shaky with WiFi regardless of where i am, but not at school.

I checked my friend's WiFi and everyone had both of them showing but mine can't find any networks.

I tried clicking other network and typing in the name and password, that didn't work.. i tries restarting my phone a few times, and when that didn't work I reset all settings...

Nothing is working.

I need the WiFi for school this is very frustrating