nodejs初步学习遇到错误

1.server.js代码如下(在桌面的node文件夹中)

var http=require("http");
http.createServer(function(req,res){
res.writeHead(200,{'Content-Type':'text/plain'});
res.end('Hello word\n');
}).listen(8888);
console.log('server running at http://127.0.0.1:8888/');

2.cmd中运行server.js报错