mysqli prepared update

[bytM3]

hi, new to this. Will someone tell me why this doesn't update?

<?php
// Include config file
include 'getprerentdb.php';

$amtdue = 0.00;  // ****************************************
$duedate='duedate';
$prevbal=0.00;
$latechg=0.00;
$secdep=0.00;
$damage=0.00;
$courtcost=0.00;
$nsf=0.00;
$paidsum=0.00;
$id="id";
$receiptno='0';

$sql = "UPDATE payfile SET
amtpaid=?, duedate=DATE_ADD(?, INTERVAL 1 month), prevbal=?, latechg=?, secdep=?, damage=?, courtcost=?, nsf=?, hudpay=?, datepaid=?, paidsum=?
WHERE id=?";  
$stmt = $conn->prepare($sql);
$stmt->bind_param("dsdddddddsdi", $amtpaid, $duedate, $prevbal, $latechg, $secdep, $damage, $courtcost, 
$nsf, $hudpay, $datepaid,  $paidsum,  $id);
$stmt->execute();
?>

[GazMathias]

Hi,

What error messages are you seeing?

From what you have posted I can see that amtpaid, hudpay and datepaid are not declared and you have set duedate to 'duedate'.

Gaz