How to start a global variable within a function?

To: php-general@xxxxxxxxxxxxx
Subject: How to start a global variable within a function?
From: Wong HoWang <howanghk@xxxxxxxxx>
Date: Mon, 8 Aug 2005 17:03:50 +0800
Delivered-to: mailing list php-general@xxxxxxxxxxxxx
Delivered-to: ezmlm-scan-php-general@xxxxxxxxxxxxx
Delivered-to: ezmlm-php-general@xxxxxxxxxxxxx
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type; b=i5CYBlmuYVKz0+yFs+5rn6ZMUxfsJPa5POq0/HZIEAGyzDn9+ObmipwPU84gmdcxcKJOQUb14DgHjrisETVOsjQpk8QhrzgGO1tDbGz2XYLHkeBQgZtvGAHLRn7J7N8LaSsYfxk8abSz/+PDrbaSih1Fw5ankrD06qHL3SgpoE0=
List-help: <mailto:php-general-help@lists.php.net>
List-post: <mailto:php-general@lists.php.net>
List-unsubscribe: <mailto:php-general-unsubscribe@lists.php.net>

as title, how to start a global variable within a function?

Follow-Ups:
- Re: How to start a global variable within a function?
  - From: Jasper Bryant-Greene