Zrušenie akcie

<?php
require("db.php");
if (isset($_POST['submit']) )
{
if (
empty($_POST['loginBox']) &&
empty($_POST['passwordBox']) &&
empty($_POST['forenameBox']) &&
empty($_POST['surnameBox']) &&
empty($_POST['add1Box']) &&
empty($_POST['add2Box']) &&
empty($_POST['add3Box']) &&
empty($_POST['postcodeBox']) &&
empty($_POST['emailBox']))
{
die("Nezadali ste všetko");
}
$addsql = "INSERT INTO
customers (forename, surname, add1,
add2, add3, postcode, phone, email, registered)
VALUES('"
. strip_tags(addslashes(
$_POST['forenameBox'])) . "', '"
. strip_tags(addslashes(
$_POST['surnameBox'])) . "', '"
. strip_tags(addslashes(
$_POST['add1Box'])) . "', '"
. strip_tags(addslashes(
$_POST['add2Box'])) . "', '"
. strip_tags(addslashes(
$_POST['add3Box'])) . "', '"
. strip_tags(addslashes(
$_POST['postcodeBox'])) . "', '"
. strip_tags(addslashes(
$_POST['phoneBox'])) . "', '"
. strip_tags(addslashes(
$_POST['emailBox'])) . "',1)";
mysql_query($addsql);
$password = ($_POST['passwordBox']);
$login = "INSERT INTO
logins (customer_id, username, password)
VALUES(" . mysql_insert_id() . ", '"
. strip_tags(addslashes(
$_POST['loginBox'])) . "','$password')";
mysql_query($login);
echo "Registration completed";
?>
<meta http-equiv="refresh" content="5; url=login.php">
<?php
}
else
{
require("header.php");
echo "<form action='" . $SCRIPT_NAME . "' method='POST'>";
?>
<table>
<tr>
<td>Login</td>
<td><input type="text" name="loginBox"></td>
</tr>
<tr>
<td>Password</td>
<td><input type="password" name="passwordBox"></td>
</tr>
<tr>
<td>Forename</td>
<td><input type="text" name="forenameBox"></td>
</tr>
<tr>
<td>Surname</td>
<td><input type="text" name="surnameBox"></td>
</tr>
<tr>
<td>House Number, Street</td>
<td><input type="text" name="add1Box"></td>
</tr>
<tr>
<td>Town/City</td>
<td><input type="text" name="add2Box"></td>
</tr>
<tr>
<td>County</td>
<td><input type="text" name="add3Box"></td>
</tr>
<tr>
<td>Postcode</td>
<td><input type="text" name="postcodeBox"></td>
</tr>
<tr>
<td>Phone</td>
<td><input type="text" name="phoneBox"></td>
</tr>
<tr>
<td>Email</td>
<td><input type="text" name="emailBox"></td>
</tr>
<tr>
<td></td>
<td><input type="submit" name="submit" ></td>
</tr>
</table>
</form>
<?php
}
require("footer.php");
?>

$premenna = trim( $_POST['premenna'] );
//odstrani setky medzeri
if( empty( $premenna ) ) {
//vypis chybu
} else {
//premenna je OK, pouzi ju ako $_POST['premenna']
}