How to find the code to open a Oracle Form.

 Hi,

In R12 many are HTML Pages , to find the code behind these pages we normally enable the FND Personalize profile option and then open the HTML Page and see the code by click on the "Personalize page". Of course most forms are select commands. IN the same way how can we find the code for Oracle Form, say there is purchase order summary form, and we populate PO number and click on the find button will open the PO details. So, what is the code has executed while open PO summary form?