Confirm box

<?php
if(isset( $_POST['btnWis'] )){
$woonpakket = $_POST['selWoonpakket'];

if ($woonpakket == "0"){
?>
<script language="javascript">
if(confirm('Are you sure you want to delete tihs record?')) {
document.write("<?php $confirm = '1' ?>");
}
else {
document.write("<?php $confirm = '0' ?>");
}
</script>
<?php
if ($confirm == "1"){
//achterhaal het nummer van de subofferte
$query = ("SELECT `woonpakketid` FROM `tblOffertes` WHERE `id` = $offerteid ");
$result = mysql_query($query) or die(mysql_error());
$obj = mysql_fetch_object($result);

//delete de subofferte uit de desbetreffende tabel
$query = ("DELETE FROM `tblWoonpakket` WHERE `tblWoonpakket`.`id` = $obj->woonpakketid LIMIT 1");
mysql_query($query) or die(mysql_error());

//zet in offerte tabel neer dat er geen subofferte meer is
$query = ("UPDATE  `tblOffertes` SET  `woonpakketid` =  '0' WHERE  `tblOffertes`.`id` =$offerteid");
mysql_query($query) or die(mysql_error());
}//einde if confirm
}//einde verwijderen woonpakket
?>