Restrict Leave approval on last week of the month.

Hi,

Recently got a requirement from client that all the leaves applied must not get approved in the last week of the month. This issue was raised by the Payroll guys as IT2001 postings are creating problems while running payroll. I suggested to stop the scheduling of report RPTARQPOST for that particular period but the client didnt agree instead asked to restrict the approvals i.e throw an error when the managers try to select "approve" button. So i need to go by client's decision but i need help on how to restrict. Is there any BAdi for this or any other alternate flexible solution available.

Reply will be appreciated.

Regards,

Abdullah Khan