Subtotal Row in Table.

Hi,

I am trying to develop a form using Adobe LiveCycle Designer. In my form i have a table which has two columns Amount and Currency. I have to introduce a subtotal line whenever the currency changes. Something similar to:

Line Item Amount Currency

1 100 USD

2 200 USD

300 USD

3 100 EUR

4 200 EUR

300 EUR

Please do give suggestion how this can be achieved.

Thanks & Regards

Ashutosh