How to remove “setting session.bug_compat_42 or session.bug_compat_warn” Warning

Warning: Unknown: Your script  possibly relies on a 
session side-effect which existed until PHP 4.2.3.
Please  be advised that the session extension
 does not consider global variables as a 
source of data, unless register_globals is enabled.
You can disable this  functionality and 
this warning by setting session.bug_compat_42
 or  session.bug_compat_warn to off, respectively. 
in Unknown on line 0.

$_SESSION['type'] = $type;

$_SESSION['category_type'] =  $type;