Help with leader board code

Hi

I have the following code which logs the user into Google Play Game Services.

I am following this tutorial

http://coronalabs.com/blog/2013/06/25/tutorial-introducing-google-play-game-services/

In the LoginCallback I am trying to work out of the call was successful.

The line

event.isError does not seem to work, if I delete all code in this function I get the Google play service icons.

I got that from this code

http://docs.coronalabs.com/daily/plugin/gameNetwork-google/init.html

[lua]

function GameNetwork:LoginCallback( event )

if not event.isError then

native.showAlert( “Success!”, “”, { “OK” } )
else
native.showAlert( “Failed!”, event.errorMessage, {“OK”})
print("Error Code: ", event.errorCode)
end

end

function GameNetwork:GPGSInitCallback( event )
print(“GPGSInitCallback”)
self._gameNetwork.request( “login”, { userInitiated=true, listener= function() self:LoginCallback(event) end } )
end

function GameNetwork:SetUp()
print(“SetUP”)

if ( system.getInfo(“platformName”) == “Android” ) then
self._gameNetwork.init( “google”, function() self:GPGSInitCallback(event) end )
else
self._gameNetwork.init( “gamecenter”, function() self:LoginCallback(event) end )
end
end
[/lua]