Showing Image after user input

I am trying to show an image using JavaScript after a user fills out an input field. I have gotten it to show the URL when using a input type="text" but when I try change it to an img tag it returns [object Object]. Is this possible to do?

input.php

<div class='col1;'> <img style='width:20%' src="" alt="" id="img" ></div>
<script type="text/javascript">
$(document).ready(function() {
    function myrequest2(e) {
        var mn = $('.auto2').val();
        var pn = $('.auto').val();

        $.ajax({
                method: "GET",
                url: "autofill2.php",
                dataType: 'json',
                data: {
                        inputmn: mn,
                        inputpn: pn
                },

                success: function( responseObject ) {
                        var x = $('#img').val( responseObject.image);
                        document.getElementById("img").src = x;
                        document.getElementById("img").alt = x;
                    },
                    failure: function() {
                            alert('fail');
                    }
            });
    }

    $('#mn').change(function(e) {
            e.preventDefault();
            myrequest2();
        });
    });

</script>

autofill2.php

<?php
$conn = mysqli_connect($host, $username, $password, $db);

$inputmn = $_GET['inputmn'];
$inputpn = $_GET['inputpn'];
$return = mysqli_query($conn, "SELECT image FROM parts WHERE ModelNum = '$inputmn' and PartNum = '$inputpn' LIMIT 1");
$rows = mysqli_fetch_array($return);
$formattedData = json_encode($rows);
print $formattedData;

?>

Also, I know that I need prepared statements. Just getting this to work first