*  Example:
 *      Default Display: (Make sure to configure the form in a chunk) - Default mode to signup
 *         - Display subscription form
 *         - Display unsubscribe form
 *         - Display newsletter admin for sending out page/document
 *                                    - Can be accessed using &npid on querystring, which refer to document id to be sent
 *         - Display newsletter admin for sending out plain text
 *
 *      To display send document link on individual page (You need administration prviledge to have this anchor appeared
 *      It's suggested to use cache for anchor, to optimize the site speed.
 *        
 *
 *      NOTE: - Notice the uncached calling to the snippet, so that the generated html is not being cached by MODx
 *            - All newsletter calling with mode can be achieved the same way with querystring &mode
 *            - Please customize all the forms provided with chunks, which can be added on snippet calling,
 *              and pay attention to the hidden field on the forms, which contain important configuration for newsletter
 *            - More information on snippet parameters, please read the code section on "SETTING UP SNIPPET PARAMETERS"
 *            - Don't forget to create document group and web group to restrict usage of the newsletter
 *            - Please include &emailGroup parameter in snippet calling for specific web group to be used, or it will
 *              caused several security issue.