wahahaha~
sorry for anyone's trouble, but i got it~
<?php
echo get_magic_quotes_gpc(); // 1
echo $POST['lastname']; // O\'reilly
echo addslashes($POST['lastname']); // O\\'reilly
if (!get_magic_quotes_gpc()) {
$lastname = addslashes($POST['lastname']);
} else {
$lastname = $POST['lastname'];
}
echo $lastname; // O\'reilly
$sql = "INSERT INTO lastnames (lastname) VALUES ('$lastname')";
?>