This question which you had answered was deleted 10 hours ago: https://stackoverflow.com/questions/14515695/js-game-assistance
And since the SE engine likes to convert this answer to a comment when posting it, here's the content of your deleted answer:
You need to use some server side language like php so that when the user play for the first time then you mark that in the database and you need to check that before running the game.
You can store the ip information if you don't have any other details to store
Since that answer had zero votes there is indeed no way to find that on your own - even I had to go through your deleted answers and check which one was deleted today.