Why did my wi-fi stop working?

I recently bought an iPod touch and it was working perfectly for a couple of days. Seemingly out of the blue, my wi-fi stopped working correctly. My touch would find the network, connect for about 30 seconds, and then lose the network and not be able to find it again. Ive browsed around and tried all of the troubleshooting and reseting that everyone seems to be trying. No matter what i try i still cannot connect to the internet on my touch. If anyone has had this problem and was able to fix it, please help me!