var http = require('http');
var querystring = require('querystring');
var postData = querystring.stringify({
	'content': '老师下次更新什么时候啊?',
	'cid': 348,
});

var options = {
	hostname: 'www.imooc.com',
	port: 80,
	path: '/course/docoment',
	method: 'POST',
	headers: {
		'Accept':'application/json, text/javascript, */*; q=0.01',
        'Accept-Encoding':'gzip, deflate',
        'Accept-Language':'zh-CN,zh;q=0.8',
        'Cache-Control':'no-cache',
        'Connection':'keep-alive',
        'Content-Length':postData.length,
        'Content-Type':'application/x-www-form-urlencoded; charset=UTF-8',
        'Cookie':'//Cookie数据就不贴出来了，是直接复制粘贴过来的',
        'Host':'www.imooc.com',
        'Origin':'http://www.imooc.com',
        'Pragma':'no-cache',
        'Referer':'http://www.imooc.com/comment/348',
        'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36',
        'X-Requested-With':'XMLHttpRequest'
	}
};

var req = http.request(options, function(res) {
	console.log('Status: ' + res.statusCode);
	console.log('headers: ' + JSON.stringify(res.headers));
    //为data事件注册回调函数来接受数据
	res.on('data', function(chunk) {
		console.log(Buffer.isBuffer(chunk));
		console.log(typeof chunk);
	});
	//当数据接受完毕，网络连接关闭，触发end事件
	res.on('end', function() {
		console.log('评论完毕!');
	});
});

//当有错误发生时候
req.on('error', function(e) {
		console.log("error! " + e.message);
});
//把要提交的数据写入请求体
req.write(postData);
//完成请求
req.end();

代码如上，node comment.js返回：

Status: 302

headers: {"server":"nginx","date":"Tue, 08 Mar 2016 06:51:41 GMT","content-type":"text/html","transfer-encoding":"chunked","connection":"keep-alive","expires":"Thu, 19 Nov 1981 08:52:00 GMT","cache-control":"no-store, no-cache, must-revalidate, post-check=0, pre-check=0","pragma":"no-cache","location":"/error/noexists"}

评论完毕!

看了好多遍代码，不知道哪里出了问题，，求教一下