There is no response when clicking the login button

Question

$.post('/admins.php/admins/Account/dologin',{'username':username,'pwd':pwd},function (res) {
if(res.code>0) {
reloadImag();
layer.alert(res.msg,{icon:2});
}else{
layer.msg(res.msg);
setTimeout(function (){window.location.href = '/admins.php/admins/Home/index'},1000);
}
},'json');
}

Nothing happens when you click to log in, but there will be a prompt if the password and user name are entered incorrectly. I have turned off the password and username verification on the front-end page. I just can’t find any reason

Answer 1

<script  type="text/javascript" >

layui.use(['layer'], function(){

  $ = layui.jquery;

  layer = layui.layer;

});

Answer 2

F12 or var_dump($_POST) to see if there is any data. . .