Add download pdf button in popup view

Is it possible to add a custom button that downloads pdf ?

ive tried doing it but i only get create button from this example: Link here

'searchInputs' => array(
    1 => 'payment_date',
    2 => 'payment_stage',
    3 => 'or_no',
),
'create' =>
    array(
        'formBase' => 'PrintPayment.php',
        'formBaseClass' => 'PrintPayment',
        'getFormBodyParams' => array('', '', 'PrintPaymentSave'),
        'createButton' => $mod_strings['LNK_NEW_PAYMENT']

    ),
<?php
if(!defined('sugarEntry') || !sugarEntry) die('Not A Valid Entry Point');
require_once('include/SugarObjects/forms/FormBase.php');

class PrintPayment extends FormBase {

    var $moduleName = 'PrintPayment';
    var $objectName = 'PrintPayment';

    function handleSave($prefix, $redirect=true, $useRequired=false){
        require_once('include/formbase.php');
        $focus = new PrintPayment();
        $focus = populateFromPost($prefix, $focus);
        $focus->save();

    }
}

is there any other way to add an download functionality ?