When splitting, autocalculate and add remaining amount

[sarjanwebdev]

As is

User is editing a transaction of $100 and opens splitter dialog.
User changes amount to $37.
User has to calculate remaining and add a split.

To be

• System should autocalculate and add remaining amount $63.
• System should always display original amount ($100).
• System should disallow save & close the splitter dialog until the total amount matches original amount ($100).

[n-stein]

I think this would only work the very first time the transaction is created before any splits are entered. Once splits are entered you can no longer adjust the amount on the transaction directly.