Wordpress Child Themes

Question

I'm trying to redeclare a function in a wordpress child theme that is already in use by the parent theme. However, I get a "Fatal error: Cannot redeclare" message when trying to do so.

Also, I've tried using the following with no luck:

if (!function_exists('jr_load_scripts')) {
  // do fancy things here...
}

Here's the link if you want to have a quick look...

EDIT: Here's the full code:

if (!function_exists('jr_load_scripts')) {
function jr_load_scripts() {
global $app_abbr;

$http = (is_ssl()) ? 'https' : 'http';

// load google cdn hosted scripts if enabled
if (get_option($app_abbr.'_google_jquery') == 'yes') :

    wp_deregister_script('jquery');
    wp_register_script('jquery', (''.$http.'://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js'), false, '1.4.2');
    wp_register_script('jquery-ui-custom', ''.$http.'://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js', false, '1.8');

else :

    wp_register_script('jquery-ui-custom', get_bloginfo('template_directory').'/includes/js/jquery-ui-1.8.custom.min.js', false, '1.8');

endif;

wp_enqueue_script('jquery');
wp_enqueue_script('jquery-ui-custom');

wp_enqueue_script('jquery-tag', get_bloginfo('template_directory').'/includes/js/jquery.tag.js', array('jquery'), '');
wp_enqueue_script('smoothscroll', get_bloginfo('template_directory').'/includes/js/smoothscroll.js', array('jquery'), '');
wp_enqueue_script('lazyload', get_bloginfo('template_directory').'/includes/js/jquery.lazyload.mini.js', array('jquery'), '1.5.0');
wp_enqueue_script('elastic', get_bloginfo('template_directory').'/includes/js/jquery.elastic.js', array('jquery'), '1.0');
wp_enqueue_script('fancybox', get_bloginfo('template_directory').'/includes/js/jquery.fancybox-1.3.4.pack.js', array('jquery'), '1.3.4');
wp_enqueue_script('qtip', get_bloginfo('template_directory').'/includes/js/jquery.qtip.min.js', array('jquery'), '1.0.0-rc3');
wp_enqueue_script('general', get_bloginfo('template_directory').'/includes/js/theme-scripts.js', array('jquery'), '3.0');

$jr_enable_indeed_feeds = get_option('jr_enable_indeed_feeds');
if ($jr_enable_indeed_feeds=='yes') :

     wp_enqueue_script('indeed-api', ''.$http.'://www.indeed.com/ads/apiresults.js');

endif;
}