Diagnosis
You change the reference area. This area is used by the program inorder to calculate the total amount from the amount per area unit.

Procedure
If you want to recalculate the total amounts due to the new area,confirm the warning by pressing 'Return'. Otherwise you should enterthe old area in the field again, position the cursor on the amountfields and select the function "Edit total amount". The total amountsthen remain the same when you change the area and the amount per squaremeter is recalculated on the basis of the new area.