here is a useful command to display or show what version of php you have installed in your pc, server, computer, laptop or any device where you have a unix operating system.

Execute this command:
CODE:
php -v


after you have send this command, you should see something like this:

CODE:
[root@host ~]# php -v
PHP 5.0.5 (cli) (built: Apr 26 2006 09:47:41)
Copyright (c) 1997-2004 The PHP Group
Zend Engine v2.0.5, Copyright (c) 1998-2004 Zend Technologies


if you don't get something like the above, then it means that you don't have php installed in your server.