Hi,
When you use the calculate event, LC Designer automatically sets the type to 'calculated - read only'. If you go to the Object > Value palette, you can set this to 'calculated - user can override'.
![2010-11-09_19-48-42.png 2010-11-09_19-48-42.png](/t5/image/serverpage/image-id/1475i65C8871848436FF8/image-size/large?v=v2&px=999)
Note that once the user has overidden the calculation, then the inputted value will not be updated, even if new data is inputted to other/net amount fields.
Niall