my 4s recently stopped connecting to any wifi. it does not recognize any of the wifi spots. I have tried all the fixes on the apple site unsuccessfully. I get the searching for network going around thing for about a second, then it goes off.

my 4s recently stopped connecting to any wifi--before I downloaded and installed iOS7. I had hoped the new OS would fix the problem but it does not. My phone cannot find any wifi--not even the one it recognized for a year and a half up to the day it stopped connecting. I had not changed any settings prior to the inability to find and connect to wifi. My wireless router is the same, and all other devices (including my macbook) still connect with it. Any suggestions for what I might do to get the 4s to access wifi?