My Iphone can't find any networks ANY

I Have an IPhone 3G and when I go to Wi-Fi settings, it loads for a second then nothings pops out, My brother has the same iphone as mine, but on his Wi-Fi settings, a ton of networks pop out. Anyone out there who knows how to solve my problem?

It happens all the time, turn your Wi-Fi off, then back on. If that doesn't work, turn your phone off, then turn it back on.

There's just a poor connection between the Wi-Fi and your phone