how to remove special characters

[eluser]boltsabre[/eluser]
sounds good to me... but make sure you do all your other validation before you make your call back. i.e.

Code:

$this->form_validation->set_rules('phoneNumber', 'Phone Number', 'trim|required|min_length[8]|myCustomCallBack

As regex can be quiet taxing in processing power/time. Get your input as close to validated before applying your regex to save a little overhead. It may seem trivial now, but it's a good habit to get into, especially for larger applications and complex regex stuff