Javascript+；PHP，总是下载相同的

我从网站下载文件时遇到问题

当我加载我的页面时，我无法下载正确的文件。（）但当我刷新youtube嵌入时，它会显示我的下一个视频（使用mysql），当我再次单击下载按钮时，它仍会下载上一个文件。而不是下一个文件

代码snipet:

BLANK.PHP（是我的播放器所在的页面）

函数ajax_request（）{
$（“#视频帧”）。加载（“”）；
}

VIDEO.PHP

<script>
$('#download_ajax').click(function(e) {
    e.preventDefault();  //stop the browser from following
     window.open('http://example.com/fetch/?videofile=http://www.example.com/watch?v=<?php echo $urlid; ?>','_blank');
});
</script>
<?php
//MYSQL CONNECTION
    if($_GET['p'] == 'house') {
        $hitsq = $mysqli->query("SELECT urlid FROM `***` ORDER BY RAND() LIMIT 1");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'drumandbass') {
        $hitsq = $mysqli->query("SELECT urlid FROM `***` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'hiphop') {
        $hitsq = $mysqli->query("SELECT urlid FROM `***` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'futurehouse') {
        $hitsq = $mysqli->query("SELECT urlid FROM `****` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'rock') {
        $hitsq = $mysqli->query("SELECT urlid FROM `****` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    }
?>    
<div class="video">
    <iframe name="Right" frameborder="0" height="100%" width="100%" src="https://example.com/embed/<?php echo $urlid ?>?rel=0&autoplay=1&controls=0&showinfo=0&autohide=1">
</iframe>
</div>

$（“#下载_ajax”）。单击（函数（e）{
e、 preventDefault（）；//停止浏览器执行以下操作
打开窗户http://example.com/fetch/?videofile=http://www.example.com/watch?v=","空白",；
});
这似乎意味着我们知道您的应用程序是如何工作的。也许我读得太快了，但听起来很混乱。您必须重新加载页面才能更改php输出$url_id。您的代码段中没有画布，我想您的问题的答案将涉及解释php输出和页面加载。@jesse您现在有了更好的想法吗？哪里定义了
$\u GET['p']
？我在URL中看不到它。@Twisty它的定义是blank.php？p=
<script>
$('#download_ajax').click(function(e) {
    e.preventDefault();  //stop the browser from following
     window.open('http://example.com/fetch/?videofile=http://www.example.com/watch?v=<?php echo $urlid; ?>','_blank');
});
</script>
<?php
//MYSQL CONNECTION
    if($_GET['p'] == 'house') {
        $hitsq = $mysqli->query("SELECT urlid FROM `***` ORDER BY RAND() LIMIT 1");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'drumandbass') {
        $hitsq = $mysqli->query("SELECT urlid FROM `***` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'hiphop') {
        $hitsq = $mysqli->query("SELECT urlid FROM `***` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'futurehouse') {
        $hitsq = $mysqli->query("SELECT urlid FROM `****` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    } else if ($_GET['p'] == 'rock') {
        $hitsq = $mysqli->query("SELECT urlid FROM `****` ORDER BY RAND() LIMIT 0,6");
        $hits = $hitsq->fetch_assoc();
        $urlid = $hits['urlid'];
    }
?>    
<div class="video">
    <iframe name="Right" frameborder="0" height="100%" width="100%" src="https://example.com/embed/<?php echo $urlid ?>?rel=0&autoplay=1&controls=0&showinfo=0&autohide=1">
</iframe>
</div>