ok, sometimes when you don want some errors or warning, you can disable this for good in your server.

all you have to do is follow these steps:

login as root

send command:
nano /etc/php.ini


now look for this line:
error_reporting =


Change it to:
error_reporting = E_ALL & ~E_NOTICE


restart apache server with this command:
/etc/init.d/httpd restart


here is some good information you should read about disabling this in your php configuration file: 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Error handling and logging ;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

error_reporting is a bit-field.  Or each number up to get desired error
reporting level
E_ALL             - All errors and warnings (doesn't include E_STRICT)
E_ERROR           - fatal run-time errors
E_WARNING         - run-time warnings (non-fatal errors)
E_PARSE           - compile-time parse errors
E_NOTICE          - run-time notices (these are warnings which often result
                    from a bug in your code, but it's possible that it was
                    intentional (e.g., using an uninitialized variable and
                    relying on the fact it's automatically initialized to an
                    empty string)
E_STRICT          - run-time notices, enable to have PHP suggest changes
                    to your code which will ensure the best interoperability
                    and forward compatibility of your code
E_CORE_ERROR      - fatal errors that occur during PHP's initial startup
E_CORE_WARNING    - warnings (non-fatal errors) that occur during PHP's
                    initial startup
E_COMPILE_ERROR   - fatal compile-time errors
E_COMPILE_WARNING - compile-time warnings (non-fatal errors)
E_USER_ERROR      - user-generated error message
E_USER_WARNING    - user-generated warning message
E_USER_NOTICE     - user-generated notice message
;
Examples:
;
  - Show all errors, except for notices and coding standards warnings
;
;error_reporting = E_ALL & ~E_NOTICE
;
  - Show all errors, except for notices
;
;error_reporting = E_ALL & ~E_NOTICE | E_STRICT
;
  - Show only errors
;
;error_reporting = E_COMPILE_ERROR|E_ERROR|E_CORE_ERROR
;
  - Show all errors, except coding standards warnings
;
;
error_reporting  =  E_ALL

Print out errors (as a part of the output).  For production web sites,
you're strongly encouraged to turn this feature off, and use error logging
instead (see below).  Keeping display_errors enabled on a production web site
may reveal security information to end users, such as file paths on your Web
server, your database schema or other information.