jquery触发器在动态加载新内容后不起作用

我正在制作一个使用图像的投票系统，每当你点击其中一个图像时，它就会提交该图像，然后淡出并使用php页面重新加载。问题是，第一次提交是有效的，但一旦重新加载，点击图像就什么都不会做。甚至连我测试过的警报都没有。

vote.js

$('.firstDisplay').on("click", function () {
    alert("work1");
    var win = $(this).attr("title");
    var loss = $('.secondDisplay').attr("title");
    send_vote(win, loss);
    console.log("<-CLIENT-> Click: Sent vote");
});
$('.secondDisplay').on("click", function () {
    alert("work2");
    var win = $(this).attr("title");
    var loss = $('.firstDisplay').attr("title");
    send_vote(win, loss);
    console.log("<-CLIENT-> Click: Sent vote");
});
function send_vote(win, lose) {
    var data = {'win': win, 'lose': lose};
    $.ajax({
        type: "POST",
        url: 'actions/send-vote.php',
        data: data,
        success: function (html) {
            $('#sent-vote').css('display', 'block');
            $('#sent-vote').fadeOut(2000);
            $('.imageBtn').fadeOut(2000);
            $('#imageDisplay').load("source/templates/vote.php");
            console.log("<-SYSTEM-> Ajax request sent and processed.");
        },
        error: function(e) {
            $('#fail-vote').css('display', 'block');
            $('#fail-vote').fadeOut(2000);
            console.log("<-SYSTEM-> Ajax request failed to process.");
        }
    });
}

vote.php

<?php
$maximumPersons = 95;
$firstDisplay = rand(1, $maximumPersons);
$secondDisplay = rand(1, $maximumPersons);
function getScore($photo_id) {
    $query = "SELECT *
                  FROM photo_scores
                  WHERE photo_id='".$photo_id."'";
    $result = $database->query_select($query);
    return $result;
}
?>
                    <a href="javascript:void(0);" class="imageBtn" id="firstDisplay" title="<?php echo $firstDisplay; ?>">
                        <img src="<?php echo $baseURL; ?>/images/persons/<?php echo $firstDisplay; ?>.png" />
                        <?php // $scoreFD = getScore($firstDisplay); echo "Wins: ".$scoreFD["wins"]." Losses: ".$scoreFD["losses"].""; ?>
                    </a>
                    <a href="javascript:void(0);" class="imageBtn" id="secondDisplay" title="<?php echo $secondDisplay; ?>">
                        <img src="<?php echo $baseURL; ?>/images/persons/<?php echo $secondDisplay; ?>.png" />
                        <?php // $scoreSD = getScore($secondDisplay); echo "Wins: ".$scoreSD["wins"]." Losses: ".$scoreSD["losses"].""; ?>
                    </a>

所有加载都是正确的，只是img/按钮在重新加载后不会提交/工作。