customization on Leave Process in AX

Dear all my DAX friends …[:)]

My team led give me a Task Like , create a form for Leave Process of employs…

Here is my challenges…

– The academic year is (EX:- jan 2014 to dec 2014), Every academic year have 12 leaves ., Employ can use only '1 'leave per month. if the employ can’t take any Leave in first month(JAN) it carry forward to next. after 3 months(4 th month APRIL) he take 1 leave ,it show remain leaves(3)… After academic year is end The leaves goes to ZERO.

EX:- emp1 can asses only 1 leave in JAN ,out of 12 leaves …