Crystal Reports New to CR

Message

     Hi Everybody,

I'm new with Crystal Report and I have a few questions. 

I have a table who has an attribute which is a foreign key of the table 
itself. 

	Code:
	Company {id, compName}
Department {id, companyId, departmentId, depName}  
- we can then have sub departments
- departmentId will be null if it's the top level

Report {id, companyId, report}
Work {id, reportId, departmentId, work}
I need to display something like this:

	Code:
	Departments Name                         Nb Work
Dep 1                                       5  //Sum of Sub Dep 11 and SubDep 12
  Sub Dep 11                                3 // Sum of Sub Sub Dep 111 and Sub Sub Dep 112
     Sub Sub Dep 111                        1
     Sub Sub Dep 112                        2
  Sub Dep 12                                2 // Same process than Sub Dep 11
     Sub Sub Dep 121                        1
     Sub Sub Dep 122                        1
     Sub Sub Dep 123                        0 // I would like to display 0 for the departments without works
Dep 2                                       4 // Same process than Dep1
  Sub Dep 21                                1
  Sub Dep 22                                0 
  Sub Dep 23                                3
What I have so far:

Parameter entered by user: 

Sort data by Company.Id AND Report.Id

I have a group on the Department.id

To calculate nb work: count ({Work.departmentId}, Department.id)

How can I:

1) Indent depending on the department level

2) Have zero for the departments without works

3) The sum of the sub departments for departments with sub departments

Thanks a lot

saphir