fine hariharan
you can have your stock as array
in your form you can have
private
String stock[];
and getter and setter
then in your jsp
<html:text property="stock"/>
now you will get array of stocks.
but you have to take care of adding new stock.
after clicking the add new button you have to call the action and add the total value of the stocks.
and set it in to the request or your form
<logic:terate.....>
<html:text property="stock"/>
</logic:iterate>
now your property have the all new dynamic properties
now in action you will get
String stocks[] =actionform.getStock();