<?php
 
$aPhoneNumber = array(
    "+3999999999999",
    "003999999999999",
    "3999999999999",
    "39 99999999999",
    "+ 39 999 99999999",
    "0039 99999999999"
);
 
foreach ($aPhoneNumber as $p) {
    print ereg_replace("^\+|^00|[^0-9]", "", $p) . "\n";
}
 
?>