Nagios Plugin for Oscommerce needed


Hello Friends,

I was searching for nagios plugin for monitoring web sequence for my oscommerce software so it should simulate and monitor, like a user logged in , purchase some product in my website , till to the end of payment page. Is there any standard plugin available for this purpose, or can we easily customize some existing plugin more easily to meet this purpose. Or can you guide me how to develop such a plugin to make custom plugin for monitoring web sequence. All sort of help will be appreciated

Thanks and Regards,