error CS0117: `UnityEngine.NetworkReachability

Hi All,
I am new to Unity, i tried to ‘build and Run’ the game app in order to create the apk for android and i get this error:

Assets/script/clickButton.cs(153,117): error CS0117: UnityEngine.NetworkReachability' does not contain a definition for ReachableViaWiFiNetwork’

i have created keystore, all i want to do now is build and run.
i have googled and searched but nothing tells me what to do.
Please help!!! Thanks

Just use ReachableViaLocalAreaNetworkinstead of ReachableViaWiFiNetwork.