How to control data input useing validation

[Balachandran]

Dear all

I am having a requirement.

While doing the budget format for 9-10 we have mandays budget. Utilization
of the man power is to various activites say 20 to 30 activites. I want to
restrict the operator not to exceed total mandays planned to mandays budgeted

I will elaborate

Let c10- Mandays budgeted 300

at c20 to c50 detailed plan for utilisation of the labour to various
activities

ie. c20 Vechicle celaning 10
c21 Helper to celaner 10
c22 ---- 10
c23 --- 5 so on

When the person doing the budgeting tries to enter at c21 he shall be
promted that mandays left is only 290-- and so on ( 300-10)

Thanks in advnce