<?php

function fish_civicrm_buildForm( $formName, &$form )
{
    $defaults = array();	
    $id = null;
    
    if ($formName == 'CRM_Contribute_Form_Contribution_Main') {
		$id = $form->getVar('_id');
       
switch($id) {
            case 5:
                $defaults = array('amount'             => 423, // the value of the amount radio NOT the dollar amount for installments
                                  'is_recur'           => 1,
                                  'frequency_interval' => '1',
                                  'frequency_unit'     => 'month',
                                  'installments'       => 7 );
                break;
        }

        if (count($defaults)) {
            $form->setDefaults($defaults);

            // also freeze these elements
            $elementNames = array_keys($defaults);

            foreach ($elementNames as $element) {
		$elm =& $form->getElement($element);
		$elm->freeze();
            }
        }
    }
}