DUTOIT It didn't worked for me and a lot of other people. See the comments!
I achieve this 2 months ago
you need to make a registration system with database...
at the first time, I suggest to download XAMPP to make a local server.
after that, you need to make a database, and with the php you need to make a connection with the database and make some code to make a registration and send the information to the database.
construct2 will update the info with GET and POST like: registration.php?user=blabla&password=123456
when you make a variable in construct2 like user and pass, you need to get the information with AJAX with a "request" url, like:
you need to find some example on the web, and about this topic there are a lot of example with php and mysql