无法通过PHP将值从输入标记传递到数据库

Question

我正在创建一个网页，并使用javascript显示总价：

function calculateTotal() {
    var price = document.getElementById("price");
    price.value = getCodeValue() * twoWeekPrice();
}

然后在输入标记中使用：

<label>Total Price</label>
<input id="price" type="text" name="totalprice" value="">

然后将其传递到另一个页面“insertbooking.php”，并将其添加到数据库中：

$getname = mysqli_real_escape_string($conn, $_POST["name"]);
$getnum = mysqli_real_escape_string ($conn, $_POST["telephonenum"]);
$getemail = mysqli_real_escape_string ($conn, $_POST["email"]);
$getcheckin = mysqli_real_escape_string ($conn, $_POST["checkin"]);
$getnumdays = mysqli_real_escape_string ($conn, $_POST["numdays"]);
$getprice = mysqli_real_escape_string ($conn, $_POST["totalprice"]);

$convertdate = date('Y-m-d', strtotime($getcheckin));

$insertquery = "INSERT INTO booking ( id, name, telephonenum, email, checkin, numdays, price) VALUES (NULL, '$getname', '$getnum', '$getemail', '$convertdate', '$getnumdays ', '$getprice)"; 

但是当我尝试在网站上发表任何想法时，我会遇到错误？