在localhost上运行时，getjson请求失败

Question

getjson请求失败，当我在我的远程主机中运行时没有问题，但是当我在localhost中运行时，请求失败，出了什么问题？我收到了这个错误：

  

SyntaxError：意外的令牌＆lt;在位置0的JSON中

我的目录：

客户端

$(document).ready(function() {


    var getdetails = function(id) {
        return $.getJSON("20.php", {
            id: "1"

        });
    } //END FUNCTION getdetails

    var searchData = function(user) {

        getdetails(user)

            .done(function(response) {

                if (response.success) {

                    $.each(response.data.users, function(key, value) {

                        $.each(value, function(userkey, uservalue) {});
                    });
                } else {
                    alert("Fail");
                }
            })
            .fail(function(jqXHR, textStatus, errorThrown) {
                alert(errorThrown);
            });
    }; //END FUNCTION searchData


    searchData("1");


    var socket = io();


    socket.emit('room', prompt('suscribe to channel...'));




});

SERVER

var app = require('express')();
var express = require('express');
var http = require('http').Server(app);
var io = require('socket.io')(http);
app.use(express.static('./public'));
var users = [];
var nicks = new Array();

app.get('/', function(req, res) {
    res.sendFile(__dirname + '/index.html');
});


io.sockets.on('connection', function(socket) {

    socket.on('room', function(room) {



socket.join(room);

    });


});




http.listen(3000, function() {
    console.log('listening on *:3000');
});