_form.phtml build custom using functionality of original

Hey, Ok so ive made a new _form.phtml called _form-2016.phtml, within this is

Code:

<?php
/**
* To improve readability, form template is made as class
* in your template you can extend it or implement it completely
* another way (not recommended :) )
*/
/* @var $form Am_Form */
$renderer = new Am_Form_Renderer_User();
// you can customize form output - for example
// $renderer->setTemplateForClass('html_quickform2_container_fieldset', '<fieldset{attributes}><qf:label><legend id="{id}-legend">&nbsp;&nbsp;{label}</legend></qf:label>{content}</fieldset>');

/* @var $renderer HTML_QuickForm2_Renderer_Default */
echo $form->render($renderer);

I would like to edit some of the fields in the original form more specific the coupon filed.
What is the best way of doing this ?
Thanks.

Hi Alexander,

Thanks for your replay.

I need to custom build a full form page, the full works i need to build a template with JS applied to the fields (blocks) and to have control over where the blocks are positioned .