If he/she is under EA, then he/she is entitled to AL but can't take it.
In probation period, leave taken is consider Unpaid Leave. For the AL, it will be pro rate and after finish probation, he/she can take all the prorate AL.
Staff AL = 12
Probation period = 3 month
Join Date = 01/01/2011
So for 01/01/2011 to 31/03/2011 any leave is consider unpaid. But he/she entitled 3 days AL.
After probation period 01/04/2011 he/she can take the 3 days AL.