What is register globals in php?
Globals (global variables) are variables which are valid
globally, which means they are available not only in a single
function but "generally" throughout the script. register_globals is
a switch which is defined in php.ini activating/deactivating this
behavior. Since register_globals and the concept of globals is said
to be removed for PHP6, it is advised to keep globals off and do
not use global variables at all.