How to add form on ubercart checkout complete page? I have latest Ubercart 7.x-3.6 on Drupal 7.31 installation.
I want to add a form on cart/checkout/complete page. which api can I use to add a form on checkout complete page.

EDIT:

Ubercart's core cart checkout complete page contain an order submit message and created order link, right? Now I want to add a form bellowed to the contents of checkout complete page. I think its enough detail.
Create a custom module and use hook_form to create your form.

Then I would do as suggested in this post to add your custom form to the ubercart page you wish to edit, only instead of rendering items, call your new function.  Does that make sense?