Workflow for Drupal 6.2

Hi,

Im creating a site using Drupal 6.2.
I need to integrate the workflow module with this.

the funtionalities i need are

1. users will submit cases (page with details along with attachments (video, pdf, doc etc))
2. this will go to the reviewer, who reviews this,
   if rejected to notify the submitter with reasons
3. If accepted, it should go to approvers, after accepting the case gets submitted.

Do we any inbuilt module in Drupal to do this functions (like workflow in Drupal 5) in Drupal 6 or is there any other way of doing this in Drupal 6.2

Thanks
Sumesh