AJAX：如何将变量的值从ajax写入'div'标签？

I have fetched the variables from the php file through Ajax and now I want to write the values to a div tag. But Ajax doesn't seem to be working.

Here's my script.

<script>
var card_number;
var book_issued;

function here(card_numb) {
    alert("pk!");
    $.ajax({

        url: 'details.php', //This is the current doc
        type: "GET",
        dataType: 'json', // add json datatype to get json
        data: ({
            card_number: card_numb
        }),
        success: function(data) {
            console.log('card_number:' + data.card_number + 'book_issued:' + data.book_isued);
            $('#adiv').html('hello world!');
        }
    });
}

For now I am trying to pass 'hello world' string but it ain't working.

This is my details.php

<?php

if (isset($_GET['card_number'])) {
$card_number = $_GET['card_number'];

$query     = "Select * from users where card_number = '" . $card_number . "'";
$query_run = mysqli_query($link, $query);
$row_numb  = @mysqli_num_rows($query_run);
if ($row_numb == 0) {
    echo "<div class='bdiv1'>No such number found!</div>";
} else {



    $row   = mysqli_fetch_assoc($query_run);
    $book1 = $row['user_name'];



    $arr = array(
        'isued_book' => $book1,
        'card_number' => $card_number
    );
    print_r(json_encode($arr));


}

HTML page card_number1.php

<input type="text" id="lab_card_number" name="lab_card_number" placeholder="Card Number" class="input" maxlength="5">

Then again a script tag to send the request to ajax script.

<script>
document.getElementById('lab_card_number').onkeydown = function(event) {
    if (event.keyCode == 13) {
        var card_numb = document.getElementById("lab_card_number").value;
        // alert(card_numb);
        here(card_numb);
    }
}
</script>