Tap the iPad's Home button to reach the home page. Then tap the "Settings" app icon
Tap Wi-Fi to enter the iPad's wireless settings
Select the ntu-wifi network. Fill in your NTU username and password and tap Join.
You will be presented with the Certificate below. Tap Accept
You will then be connected to ntu-wifi
Switching off Wi-Fi
Tap Settings icon
Move the "Wi-Fi" slider from On…
Disconnecting from a WiFi network
If you are using a shared iPad, it is essential that you remove your connection from the network, or another user may unwittingly connect using your remembered credentials.
Once more, tap the Settings icon, followed by WiFi, Underneath Choose a Network tap the blue/white arrow to the right of the selected connection.
You should now see this screen:
Tap Forget this Network
Click Forget to confirm. You can now exit the Settings screen. This network will no longer be remembered. If you want to re-join it you will have to submit your credentials again.