PHP Fatal error: Class 'URL' not found in /var/www/html/laravel/firstlvproject/config/settings.php

I was trying to implement jquery file upload plugin usibghttp://ift.tt/1T29aqV and i am getting error on URL::to_route, even for path(). Below is the settings. php code which was given in their doc. I am very new to laravel, any help please

 return array(
    //'script_url' => URL::to_route('upload'),
    'upload_dir' => path('public').'bundles/jupload/uploads/files/',
    'upload_url' => URL::base().'/bundles/jupload/uploads/files/',
    'delete_type' => 'POST',
    'image_versions' => array(
        'thumbnail' => array(
            'upload_dir' => path('public').'bundles/jupload/uploads/thumbnails/',
            'upload_url' => URL::base().'/bundles/jupload/uploads/thumbnails/',
        ),
    ),
);

via Chebli Mohamed