ChartField Combination

Dear all

I would like to better understand the concept of Chartfield Combination.

In the implementationm we are following we would like to create possible combination between account and department: we are succesfully creating them using Combo and also Master Selector, both using tree functionality.

Now once we are creating a  Journal Entry using a wrong combination, the system is moving the journal in error after edit process.

In Account Payable we cannot save the voucher if we are inserting a wrong value combination.

We are looking for the following behaviour :

- Both in General Ledger and in Account Payable we would like to insert first the account and than choose the department from the ones that together with the account are a valid combination.