Form Validation - problem with some chars

[eluser]Unknown[/eluser]
[quote author="SPeed_FANat1c" date="1337687398"]You probably will have to extend form validation class, alpha rule, now it is:\

Code:

function alpha($str)
{
  return ( ! preg_match("/^([a-z])+$/i", $str)) ? FALSE : TRUE;
}

So thats why it is not valid I think.

Or create your custom validation rule.[/quote]

Thanks. I created my own rule.