i have made up a simple function to extract a number from a string..

I am not sure how good it is, but it works.

It gets only the numbers 0-9, the "-", " ", "(", ")", "."

characters.. This is as far as I know the most widely used characters for a Phone number.

<?php
function clean_phone_number($phone) {
       if (!empty($phone)) {
               //var_dump($phone);
               preg_match_all('/[0-9\(\)+.\- ]/s', $phone, $cleaned);
               foreach($cleaned[0] as $k=>$v) {
                       $ready .= $v;
               }
               var_dump($ready);
               die;
               if (mb_strlen($cleaned) > 4 && mb_strlen($cleaned) <=25) {
                       return $cleaned;
               }
               else {
                       return false;
               }
       }
       return false;
}
?>