Hi Cgimler well done you're doing great.
Your current block could be caused by your host being cautious about cross-domain AJAX calls.
If you add the following line to the top of your php file it could well sort that for you:
(inside the php tags)
header('Access-Control-Allow-Origin: *');
Also, you might want to eventually upgrade the table to include some other fields if you'll ever want to see where specific scores are coming from, or if you want more than one group to play without affecting each other's scores.