User defined error message do not work

[eluser]Tim Brownlaw[/eluser]
[quote author="rm_beginner" date="1403694854"]

Code:

$this->form_validation->set_rules('callback_show_error_message', 'username', 'Username');

try to put your callback right side.

Code:

$this->form_validation->set_rules( 'username', 'Username', 'callback_show_error_message');

hope it works.[/quote]

That's how it's written in the user guide!

@zombie1.... I'd seriously be reading it again and checking it against what you have written.