dynamic table row value

I have created dynamic table form same as "Purchase Order form" in samples folders with Live Cycle Designer. In the form we have ADD Button, when we click that button, we will get additional rows. If i enter any any values in that rows fields, i need to collect that value and do some calculations and need to show that value in another field.

Can any one tell me how to write the javascript to get rawvalue for dynamically created rows.

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Thanks,
Mohan