I accidentally drop my iphone 4s and now the wifi is not working. It could not scan my home wifi. What could be the problem. I've tried the freezer fix and it work for a while but after few seconds the connection is cut. Is there anyway this can be fixed?

I have no idea what the "freezer fix" is, nor why anyone would think temporary exposure to cold will somehow fix a hardware issue with a 100% solid state device. Also, actually freezing your iPhone may very well itself cause damage.

If you dropped it and wifi immediately failed to work, the odds are you inflicted physical damage to it - perhaps the antennae connection internally. You could try a simple reset and see if that helps, but if not, you need to take it into Apple for an evaluation and diagnosis.

If it has internal damage, since you dropped it, your warranty no longer applies. Apple does not repair iOS devices, the merely swap them for factory refurbished units (and send your damaged one back to the manufacturer in China for refurbishment or recycling). You would ahve to pay the out of warranty replacement fee (look on your country's Apple web site, under support for the iPhone for fees).

The freezer fix? That is an urban legend.

Try resetting network settings on the iPhone at Settings > General > Reset.

If no change after that, try restoring the iPhone with iTunes as a new iPhone or not from the backup.

If no change after restoring the iPhone as a new iPhone, the iPhone has a hardware problem.

Apple offers an out of warranty or not covered under the warranty "repair" that pays for an exchange at a significantly reduce price off the full retail sales price. The exchange will be the same model, storage capacity, and color. The cost in the U.S. is around $199.00 plus tax.

The "freezer fix" is specifically for phones where the WiFi won't turn on. Likewise, the "hair dryer fix".

If WiFi turns on but doesn't connect to your home network, but does connect to other networks, start by rebooting your router by removing all power from it for 15 seconds or so.

If WiFi turns on but it doesn't connect to any network the drop probably dislodged the connection to the WiFi antenna.