How do I enable register_globals (PHP)?
Via .htaccess
For further information about .htaccess files and how they work, take a look at the following article:
How do .htaccess files work in Plesk?
The normal method is to use a .htaccess file to change the PHP settings via the php_flag directive:
php_flag register_globals on
Just create the file .htaccess with the above contents in the directory where you are going to install the application (or in the root of the domain if you want it to take affect over the whole domain). To switch if off, either change on to off or remove the line or file.