[web2py] Getting the field value of a form field

[Kenneth Lundström]

Hello,

I´m creating a form with SQLFORM(db.t_order, order_id)
so I get a form with values.
As the data has been queried from the database I´d like to get a value 
from one of the fields a do some customization based on it. But how do I 
get the value of field f_sum from the form?


Kenneth