Wireless connected but can't surf

As my home router wasn't very powerful I piggybacked a N router to it. Initially my Samsung found the network and everything was fine. Now the phone says its connected to the network but it can't connect to any websites. Turning off and connecting via 3g is not a problem
Any thoughts

metinhoca - talk to the network admin to see if your device needs to be added to the network or if there is some setting you have to use (like WEP or some such)

ddavidu - is there any security on your home network? Set your router to "no security" and see if your device can go out start trying locking network, hiding SSID etc. Again it may be a security protocol that is required. My home network is WEP - not strong but I have a lot of different devices with different ages. A neighbour's network is set to WPA2. Make sure the setting for your router is the same as the security setting for the network connection from your device.