Adobe LiveCycle Designer script to sum the values of table column.

Hallo,

I am relatively new to Adobe LiveCycle Designer, i am trying to get the sum of a decimal field "Net Value" column, and outside the table in "Term of Payment" field i am doing some calculation where i am calculating the discount amount and the total amount that the user should pay.

In this example i have 2 positions in the table, and in the initialize event of the "Net Value" subform, i am trying to sum the values of the "Net Value" column and assign it to a decimal field "decSkontoSum"  in the same subform, but unfortunately it assign just the first position value of the table as shown in the first screenshot.

 In the Initialize even of the "Term of Payment" field  i am getting the value of the "decSkontoSum" and then do the calculations of the discount with it.

 How to get the sum of the "Net Value" column i this case the sum of the two positions ? i have tried to use Sum function in the "calculate" event of "decSkontoSum" field but unfortunately it did not work.