[solved]Extended No_Space Validation, but is not working

[eluser]Unknown[/eluser]
I have attended my validation library by adding another rule for no spacing. But it is not working, is there anything i miss out?

In my "system\application\libraries" I added MY_Validation

Code:

<?php
function no_space($str)
{
    return ( ! preg_match("#\s#", $str)) ? FALSE : TRUE;
}
?>

In my "system\language\english\validation_lang"

I added this code

Code:

$lang['no_space']   = "The %s field may not contain spaces.";

In my function i call the rule

Code:

$this->form_validation->set_rules('user_username','Username','trim|required|no_space[user_username]|xss_clean');