making mandatory field on form

hi expert, i want to make finanical dimension fields on employment information form mandatory, for this i just do some reverse engineering , also make some basic field  mandatory on following tables,

DimensionAttributeValueSetItem,

DimensionAttributeValueGroup

DimensionAttributeSetItem

DimensionAttributeValue

but did not work..

in my scenario when we hire a new employee, so financial dimension for a employ not mandatory by default, i want to make it mandatory,cost center, business unit, etc, i want to make all of them mandatory when hiring a new employ.

plz guide me..

etc.