Check Quota - Absence Request Approval

Dears

             Good Day ,

This is a simple approval process for absence request

But i need more than clarification

My steps as below :

1. Create Request      (FORMABSENC - CREATE)

2. Approve Request   (FORMABSENC - Approve)

3. If approved - send mail and call PA30 screen  (EMPLOYEESU - CREATEINTERACTIVE)

4. If rejected   - send mail

My questions

1. How make validation to check the employee absence quota before creating the request

2. If the employee has more than one manager (direct Manger and manger of his manager ) how i can handle this case

3. in object EMPLOYEESU , How can pass the employee number .

Best Regards ,