自己在写项目，发现一个问题无法解决
我点击添加疑难单词就应该执行sql语句，但是它就是没反应
我想把单词插入疑难单词分类就是插不进去
<?php
require_once('conn.php');
?>
<html>
<head>
<title>单词内容</title>
<link rel="stylesheet" type="text/css" href="css/style.css">
</head>
<body>
<div class="container">
<div class="top_navigation">
<span>PHP单词管理系统</span>
<ul>
<li><a href="index.php">系统首页</a></li>
<li><a href="newscontent.php">最新单词</a></li>
<li><a href="fl.php">单词分类</a></li>
<li><a href="admin_login.php">后台管理</a></li>
</ul>
</div>
<div class="top_banner">
<img src="images/banner3.jpg" alt="banner">
</div>
<div class="news_content">
<div>
<table class="news_content_list">
<?php
if(empty($_GET['news_id']))
{
$sql1 = mysqli_query($conn,"SELECT news_id,news_title FROM news ORDER BY news_id DESC");
$info1 = mysqli_fetch_array($sql1);
$news_id = $info1['news_id'];
}
else
{
$news_id = $_GET['news_id'];
}
$sql1 = mysqli_query($conn,"SELECT * FROM news WHERE news_id=$news_id");
$info1 = mysqli_fetch_array($sql1);
?>
<tr>
<th class="tb_title">单词标题: <?php echo $info1['news_title']?></th>
<th class="tb_date">加入时间: <?php echo $info1['news_date']?> </th>
</tr>
<tr>
<td colspan="2" style="font-weight: bold">单词内容：</td>
</tr>
<tr>
<td colspan="2" style="text-indent: 2em;line-height: 22px;">
<?php echo $info1['news_content']?></td>
</tr>
</table>
</div>
</div>
<input type="button" value="添加到疑难单词" name="tj" onclick="function fas() {
}
fas()">
<?php
$conn = mysqli_connect("localhost","root","123456","news");
if(!isset($_GET['tj'])){
$sql3 = mysqli_query($conn,"update news set news_type=7 where news_id=$news_id") or die('添加失败！');
}
?>
<input type="button" value="退出疑难单词" name="itj" onclick="function off() {
<?php
$conn = mysqli_connect("localhost","root","123456","news");
$news_id = $_GET['news_id'];
if(!isset($_GET['itj'])){
$sql2 = mysqli_query($conn,"update news set news_type=1 where news_id=$news_id") or die('添加失败！');
echo "<script>alert('已退出到疑难单词');</script>";
}
?>
}
off()"/>
<div class="footer">
<p>背单词系统</p>
</div>
</div>
</body>
</html>
其中添加疑难单词按钮我点击多少次都没有反应
我自己尝试过点击事件也没有反应。但是删除疑难单词是好用的，但是添加疑难单词用不了
希望可以正常添加疑难单词
