* changed '.container' to '.container_12'
* changed class 'container' to class 'container_12'
* added user name and password for logging in
* added css properties stalactite and stalagmite which need to act as prefix as suffix for the top and bottom
* added auth-form css ID
* now redurects to open_file.php when attempting to open an unreadable file
* this file has been created to handle user authorization affairs
* factorized code a bit, login validation is now done by fns/user_handler.php
* ensured that it always redirects to open_file.php when it can't create a new file