How to exclude Required Validation for some fields?

Question

Hi,
I have a page in a form with some fields that are set as required like this:
Field 1   Field 2
table
Field 3   Field4 "Add" button
Field 5    Field 6
"Submit" button
There are two buttons in this form. The "Add" button is PPR allows adding Field 3 and Field 4 to the table. The "Submit" button is for the actual submission and processing. When "Add" button is pressed, I only want the require validation to be done for Field 3 and Field 4, but not Field 1/Field 2/Field 5/Field 6.
Currently, if I press "Add" button, the required field validations are triggered for all six fields. How can I only limit the require validation to some required fields only for this button?
Thanks
-Mina

Answer 1

subform is a great idea and kinna what I needed in this situation, but there is another challenge.
In my case, I tried to put table, Field 3 and Field 4 in subform:
Field 1 Field 2
<af:subform>
table
Field 3 Field4 "Add" button
</af:subform>
Field 5 Field 6
"Submit" button
When I press "Add" button, Required validation still triggered for all fields. Only if I put Field 1 and Field 2 in another subform, and Field 5 and Field 6 in a different subform. Then it works like this:
<af:subform>
Field 1 Field 2
</af:subform>
<af:subform>
table
Field 3 Field4 "Add" button
</af:subform>
<af:subform>
Field 5 Field 6
"Submit" button
</af:subform>
But in my case, I need Field 1, Field 2, Field 5, Field 6 and "Submit" button to be in the same subform, as the "Submit" button applies to these four fields. In the UI design, Field 3 and Field 4 are between Field 1/Field 2 and Field 5/Field 6 though.
Any other ideas?