My iPhone doesn't save the WiFi password . every time i go out of the the WiFi range and comes back i have to enter the password again . ?
I think you can go to the setting to check it, but if you forgot the wi-fi password, you can read this article about how to find out wi-fi password, it is in http://goo.gl/MmLgD4
Maybe try putting the "auto connect" on.
You can try to it manually by adding the network by selecting "Other" and filling the information instead of selecting the item from the list of network. You can also go to "setting" then to 'General' then to 'Restrictions' and turn this on.
turn ask to join networks off and known networks will automaticly be joined without a password required even if it is password protected