Phone Toshiba TG01 WM6.5 Wi-Fi problem

Well it started about 3 days ago.My phone can scan my WiFi connection but it cannot connect to it,if I select connect it will be connecting for a while but later will switch back to available.Sometimes it cannot even scan it,but rarely it will be connected but only stays for a few seconds.Then I realize other connection can work but only my connection will not work.Can someone explain the problem?