How do I create an Approval Workflow that updates the List Item that started the Workflow?

How do I create an Approval Workflow that updates the List Item that
started the Workflow?

I'm using SharePoint 2010 and I'm trying to create a workflow for a Help
Desk List that will track tickets.
Here is the (intended) business process:
User generates a new Help Desk List Item (contains description of issue) ->
A new Approval Task is created for the User's Manager (which is tracked
through another List, called Help Desk Tasks) ->
When the Manager Approves or Rejects it, the Task is updated to Complete ->
If the Manager Approves it, the original Help Desk List item should have
its Status set to In Development. If the Manager Rejects it, the original
Help Desk List item should have its Status set to Cancelled.
Right now, this doesn't work. I can either set it up as an Approval
Workflow but it won't update the fields for the Current Item, or I can set
it up as a List Workflow and I can update the fields, but the Approval
Task never starts.
Am I doing something wrong or am I missing something? Any help is
appreciated.