javascript - onclick 按钮不执行任何操作；未调用 JavaScript 函数

Question

我正在尝试使用数据库创建登录页面，但我的按钮在单击时不会执行任何操作，即使它应该带我进入下一页(index2.html)。即使在控制台中也没有显示任何内容，所以我不知道它出了什么问题。

Javascript代码

var response ="";
  function plogin(){
  var credentials = new Object();

  credentials.username= document.getElementById("user").value;
  credentials.password = document.getElementById("password").value;

  var request = new XMLHttpRequest();

  request.open("POST","/userlogin", true);
  request.setRequestHeader("Content-Type","application/json");
  request.onload=function(){

  response = JSON.parse(request.responseText);
  document.getElementById("loginform").style.display="none";
  if (response.message =="1"){
     window.location = "index2.html?username=" + credentials.username;}
  else{
     document.getElementById("msg").textContent = response.message;}

登录表单

<form id = "loginform" onclick="plogin()"> 
        <label style="color: white;">Username:</label>
        <input type="text" style="border-style: solid; border-width:5px; border-color: slategrey;" placeholder="Jon" id="user" name="username">
        <br>
        <label style="color: white;">Password:</label>
        <input type="password" style="border-style: solid; border-width:5px; border-color: slategrey;" id="password" name="password">
        <br>
        <br>
        <input type="button"  class = "btn btn-secondary" value="Login">
      </form>

两个代码都在同一个 html 页面中

用户登录代码(js)在Postman中工作

userlogin(request, respond){
        var username = request.body.username;
        var password = request.body.password;
        var msg="";

        var sql = "SELECT user.password FROM restaurant_review.user WHERE username = ?";

        db.query(sql, [username], function(error,result){
            if(error){
                throw error;
            }
            else{
                if(result.length > 0){
                    if(password == result[0].password){
                        msg ="1";
                        console.log(msg);
                    }
                    else{
                        msg = "FAIL";
                        console.log(msg);
                    }
                }
                else{
                    msg = "USER NOT FOUND";
                    console.log(msg);
                }
                respond.json(prepareMessage(msg));
            }
        });
   ```we

Answer 1

尝试在 HTML 中进行更改 <button type="submit">...</button>而不是<input type="button" class = "btn btn-secondary" value="Login">