Update is actually Deleting?

[Rexication]

$editFormAction = $_SERVER['PHP_SELF'];
if (isset($_SERVER['QUERY_STRING'])) {
$editFormAction .= "?" . htmlentities($_SERVER['QUERY_STRING']);
}

if ((isset($_POST["MM_update"])) && ($_POST["MM_update"] == "form1")) {
$updateSQL = sprintf("UPDATE users SET username=%s, password=%s, access=%s WHERE id=%s",
GetSQLValueString($_POST['username'], "text"),
GetSQLValueString($_POST['password'], "text"),
GetSQLValueString($_POST['access'], "text"),
GetSQLValueString($_POST['id'], "int"));

mysql_select_db($data, $ms);
$Result1 = mysql_query($updateSQL, $ms) or die(mysql_error());

$updateGoTo = "users.php";
if (isset($_SERVER['QUERY_STRING'])) {
$updateGoTo .= (strpos($updateGoTo, '?')) ? "&" : "?";
$updateGoTo .= $_SERVER['QUERY_STRING'];
}
header(sprintf("Location: %s", $updateGoTo));
}

$colname_Recordset1 = "-1";
if (isset($_GET['id'])) {
$colname_Recordset1 = $_GET['id'];
}
mysql_select_db($data, $ms);
$query_Recordset1 = sprintf("SELECT * FROM users WHERE id = %s", GetSQLValueString($colname_Recordset1, "int"));
$Recordset1 = mysql_query($query_Recordset1, $ms) or die(mysql_error());
$row_Recordset1 = mysql_fetch_assoc($Recordset1);
$totalRows_Recordset1 = mysql_num_rows($Recordset1);

When I do this it used to actually update but now its deleting records and I dont know why.