Amount  

This is an optional field. It defaults to Hours * Rate rounded to the precision of the system currency. The user can directly enter/override the amount. If the user overrides the calculated value, the system will not recalculate the rate. The Document Totals section at the top of the page will get updated with this amount. The amount can be positive or zero.

Changes to hours or rate should trigger recalculation of amount value if both hour and rate are specified. However, changes in amount value do not trigger any other changes.