Confuse - How represent a Set variable in jsp page to be filled

[Manuel Jordan]

Hi guys
(sorry for my grammar)

i need really your help and your experience is need it

i have a jsp page that represents a payment/buypaper form

the first part of the form could be

some fields html for addtional input such as
date of buy , numberdocument, name of company that make the payment, type of sell (cash or credit)
etc etc

now for the details it consists in an element table that has its header such as

 
<table>
<tr>
<th>Code</th>
<th>Description</th>
<th>Units</th>
<th>Amount</th>
<th>Price Unit.</th>
<th>Total</th>
</tr>
....

now each row of the table should represent the buy of the product (tv,cd etc)

i am thinking that the class for the SimpleForm should be something like this

 
public class xForm{
private Header header;
private Set details;

//accesor methods
}

where Header has its respective table for Hibernate and "details" too

my problem is how represent each possible agregation of a detail in the jsp??
each row should be unique (maybe using the idProduct).


what could be the best practice to done this???
because each detail should create and insert a row in a db table

really i need your help

some suggestion, url tutorial/code
or share here a code of course be appreciate

thanks for advanced

p.d: other pretty problem, i am using ajax to create dynamically each row (works until here), but i dont have any idea
how it could be integrate with the Set of Spring,

think how a matrix where each row have 6 textfields already filled for ajax.