send data with ajax multi input - php

Question

I try to use INSERT INTO to Database using AJAX with multi input data, but I Face some Problem when I send data more than one Input Data. Did I Missed something?
This's JS file
JAVASCRIPT
function ajaxSaveTitle() {
'use strict';
var vTitle = document.getElementById('inputTitle').value;
var vPrice = document.getElementById('inputPrice').value;
var vTitlev = "vTitlev=" + vTitle;
var vPricev = "vPricev=" + vPrice;
var tXhr = new XMLHttpRequest();
tXhr.onreadystatechange = function() {
if(this.readyState == 4 && this.status == 200) {
document.getElementById('linputTitle').innerHTML = this.responseText;
}
};
tXhr.open("POST","uploadfile.php","true");
tXhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
tXhr.send(vTitlev,vPricev);}
This is PHP file
PHP
<?php
session_start();
include_once('connect.php');
$currID = $_SESSION['user_id'][0];
if(!empty($_POST['vTitlev']) && !empty($_POST['vPricev'])) {
$fileTitle = $_POST['vTitlev'];
$fileTitle = stripslashes($fileTitle);
$fileTitle = mysqli_real_escape_string($con, $fileTitle);
$filePrice = $_POST['vPricev'];
$filePrice = stripslashes($filePrice);
$filePrice = mysqli_real_escape_string($con, $filePrice);
$qfileTitle = "INSERT INTO file (usr_ID, fileName, prc) VALUES
('$currID','$fileTitle','$filePrice')";
if(mysqli_query($con, $qfileTitle)) {
echo "Berhasil di Simpan";
} else {
echo("Error description: " . mysqli_error($con));
};
mysqli_close($con);}
?>

Answer 1

you should use send like that:
tXhr.send(vTitlev+'&'+vPricev);
it accepts a string as params: https://www.w3schools.com/xml/ajax_xmlhttprequest_send.asp

Answer 2

You have to send more data with use of &
change your send code
tXhr.send(vTitlev,vPricev);}
to
tXhr.send(vTitlev+"&"+vPricev);}

Answer 3

In case of post requests, your data should be bind with "&". Comma is invalid as send accept only one parameter.
Look at this https://www.w3schools.com/xml/ajax_xmlhttprequest_send.asp
Data should be like this
xhttp.send("fname=Henry&lname=Ford");
not this
xhttp.send("fname=Henry,lname=Ford");