Paid Absence

Dear Gurus,

I created Paid Absence type call as PL. But my client want if employee apply Paid Absence then one allowance (Transport Allowance) they want to deduct as per Paid Absence days.

Employee take PL(Paid Absence) 09.06.2010 to 11.06.2010 then they want to deduct three days Transport Allowance.

How to Map this requirement? Please Advise

Regards

MHPO