wi fi - My Galaxy Nexus detects wifi signal(at home) but can't connect to it

My Galaxy Nexus detects wifi signal(at home) but can't connect to it.

I cant connect to wifi. The wifi icon doesnt appear beside the time on the upper right of the screen. When I try to access facebook it says connection lost. But wifi works properly well on the laptop.

I've switched the ON/OFF , restarted the galaxy Nexus and still nothing.

Please help.