func whenConnected(block: Void -> Void,notConnected: ((Void) -> Void)?,showErrorMessage: Bool) -> Void {
 
        let connected = Reachability.isConnectedToNetwork()
 
        if connected {
            block()
        } else {
            notConnected?()
        }
 
        if showErrorMessage {
            // your error handling //
        }
    }