未定义的索引：使用jQuery .load（）方法提交表单时PHP中的member_passport错误

I have been struggling with this error. i'm trying to submit my form to a PHP script using the jQuery .load() method but i encounter an error that says

Notice: Undefined index: member_passport in C:\xampp\htdocs\web\includes\back-end
ew_member.php on line 7

Notice: Undefined index: member_passport in C:\xampp\htdocs\web\includes\back-end
ew_member.php on line 8

Please what am i doing wrong here. Below is my jQuery script

$("#newMember").submit(function(event){
event.preventDefault();

var reg_no = $("#reg_no").val();
var member_passport = $("#member_passport").val();
var create_member = $("#create_member").val();

$("#result").load("/web/includes/back-end/new_member.php", {

reg_no: reg_no,
member_passport: member_passport,
create_member: create_member
});
});

My Html 5 script:

 <form id="newMember" method="post" novalidate enctype="multipart/form-data">
    <div class="form-group reg_no">
    <label for="reg_no">Reg No</label>
    <input type="text" class="form-control" id="reg_no" name="reg_no" placeholder="Reg No" value="<?php echo strtoupper(generateRegNo()); ?>" disabled>
    <span class="help-block" id="reg_no_err"></span>
    </div>

    <div class='form-group member_passport'>
    <label for='member_passport'>Member Passport</label>
    <input type='file' class='form-control' id='member_passport' name='member_passport' placeholder='Member Passport'>
    <span class='help-block' id='member_passport_err'></span>
    </div>
    <button type="submit" class="btn btn-lg btn-primary" id="create_member" name="create_member" style="border-radius:2px !important;">Create Member</button>
    </form>

My PHP script

<?php
if($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['create_member'])){

$reg_no = escape_string($_POST['reg_no']);
$member_passport = $_FILES['member_passport']['name'];
$member_passport_tmp = $_FILES['member_passport']['tmp_name'];

move_uploaded_file($member_passport_tmp, "/web/images/{$member_passport}");

?>