i can't find my wifi password for iphone 4s

Many internet providers put the WiFi password on a stick on the bottom of the router they send you, so start by looking there. If you changed the password from what it was originally or didn't get the router from your provider, you'll need to determine the make and model of the router and see if you can find the manufacturer's instructions for resetting the password. You might also contact your internet service provider for assistance.

What did your internet service provider say when you called them?