How to enable and disable the PHP magic quotes directive?

When the magic quotes directive is enabled, PHP automatically escapes 
data from HTTP GET and POST requests and cookie data. For example, 
if a user types “hello” (with the quotation marks) in a form, PHP 
automatically escapes the quotation marks and stores the value as 
\“hello\”. To enable this functionality, use a text editor to 
modify the magic quotes directive in the php.ini file as follows:

magic_quotes_gpc = on

To disable this functionality, modify the magic quotes directive in the php.ini file as follows:

magic_quotes_gpc = off