suggestions
1. any variables start with $_ and $PHP_ and also $HTTP_
should be always global
no need to use such as
   global $PHP_SELF;

if possible, set_global_all(true); makes variables scope just like c/java do

2. if we access $PHP_POST_VARS['...'] and it's not set
should trigger an special warnning, not a normal warnning
cause it's not that variables we can initize
so that, we can easily turn off the special warnning without ignoring the other normal warnning.

3. we don't like
  $a = 0;
to initize an variable, we like
  int $a; // it's auto initized into 0
or
  int $a=1234;