sir i have samusng s4 gt9505.if 1st wifi connected and i want to connect to 2nd wifi the wifi going

sir i have samusng s4 gt9505.if 1st wifi connected and i want to connect to 2nd wifi the wifi going to off and never on...when i format phone then wifii connect....can u help me

Welcome to Android Central! I don't quite understand what you're asking. If you're connected to one wifi network and want to connect to a different one, go to Settings>Wi-fi, select the network, and tap Connect. If the signal is strong enough, the device should stay connected to this 2nd network. If the signal is week, it might disconnect from that 2nd network and reconnect to the first one.