The request, if I understood it correctly, was to save and resume score.
To do that with php, you have to manage the user identity too, which I think wouldn't
be too easy and "distract" from the real task.
To me the easiest way is to use shared object, you play the game, decide to exit so
save the score and close. Once you reload the flash, it resumes the score from the
shared object (much like login forms "remember me").
Of course this solution would manage only one user per machine.
As a reference you can see this: