引入所需要的插件

<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.5.1/jquery.js"></script>
<link rel="stylesheet" type="text/css"  />
<script src="https://www.layuicdn.com/layui/layui.js"></script>

ajax代碼邏輯部分

$(function(){
        $('#Submit').on('click',function(){
            var username = $('input[name=username]');
            var password = $('input[name=password]');

            if(username.val() == ''){
                layer.msg('用戶名不能為空！', {time: 1500, icon: 2});
                username.focus();
                return false;
            }

            if(password.val() == ''){
                layer.msg('密碼不能為空！', {time: 1500, icon: 2});
                password.focus();
                return false;
            }

            $.ajax({
                // async:false,
                url : "youUrl",
                data: $('#theFormId').serialize(), //<from id="theFormId"> 定義form表單id
                type:'post',
                dataType:'json',
                success:function(res){
                    //根據(jù)res 返回的數(shù)據(jù)進(jìn)行邏輯判斷
                    if (1 == res.code) {
                        if (5 == res.data.status) {
                            layer.alert(res.msg, {icon: 2},function(){
                                window.location.href = res.url;
                            });
                        }else{
                            window.location.href = res.url;

                    } else {
                        layer.closeAll();
                        if ('vertify' == res.data.status) {
                            fleshVerify();
                        }
                        
                        if (2 == res.data.status) {
                            layer.alert(res.msg, {icon: 4});
                        } else {
                            layer.msg(res.msg, {icon: 2,time: 1500});
                        }
                    }
                },
                error:function(XMLHttpRequest, textStatus, errorThrown) {
                    layer.closeAll();
                    layer.alert('網(wǎng)絡(luò)失敗，請(qǐng)刷新頁(yè)面后重試', {icon: 5});
                }
            });
        });
    });