Iphone 4S and Apple Mac

I have just purchased an Iphone 4S. When I plug into my Apple Mac the phone is not recognised on Itunes. All I get is an error message saying that the Iphone needs to have Itunes Software version 10.3 or higher. It doesn't recognise the phone to check the software on the Mac.

If I plug it into my windows laptop then it says that the software is version 6 and that this is up to date.

Any ideas how I get the phone software to work on the Apple Mac ?