如何在验证码代码用户输入正确时更新查询

Question

我想在用户输入正确的输入时创建此功能然后如果输入正确则在数据库中更新数量这些行中的PHP代码错误＆＃34;`echo $ code;

echo $user_input;
if($user_input==$code){"   what should i do ?`"

    if(isset($_POST['submit'])){
    echo $code;
    echo $user_input;
    if($user_input==$code){
        include ('db.php');

        mysqli_query($con,"update users set user_amount=amount+.0010");
        $q=mysqli_query($con,"select user_amount from users");
        $row=mysqli_fetch_row($q);
        echo '<script>document.getElementById("response").innerHTML="Correct   +.0010<br>New amount: "+'.$row[0].';</script>';
    }
}