<p>I'm trying to host a PHP web site that was given to me.  I see this warning:</p>

<blockquote>
  <p><strong>Warning:</strong> 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 <strong>Unknown</strong> on line <strong>0</strong></p>
</blockquote>

<p>What does this mean?  How might I track down the source of this problem within the code?</p>

basically you have a variable with the same name as your session. ex:
```
```
$_SESSION['var1'] = null;
$var1 = 'something';
```
```
which will reproduce this error. you can stop PHP from trying to find existing variables and warning you about them by adding these lines to your script:
```
```
ini_set('session.bug_compat_warn', 0);
ini_set('session.bug_compat_42', 0);
```
```
these values can be set in php.ini or .htaccess as well