Node.js http response file content

var http = require('http');
var fs = require('fs');
var path = require('path');


function send404(response){
    response.writeHead(404,{'Content-Type':'text/plain'});
    response.write('Error 404: Resource not found.');
    respons.end();// ww w.ja va2 s  .c  o  m
}

var mimeLookup = {
  '.js':'application/javascript',
    '.html': 'text/html'
};

var server = http.createServer(function(req,res){
   if (req.method == 'GET'){
       //resolve file path to filesystem path
       var fileurl;
       if(req.url =='/')fileurl ='/index.html';
       else fileurl = req.url;
       var filepath = path.resolve('./public'+fileurl);

       //lookup mime type
       var fileExt = path.extname(filepath);
       var mimeType = mimeLookup[fileExt];

       if (!mimeType){
           send404(res);
           return;
       }

       //see if we have that file
       fs.exists(filepath,function(exists){
          if(!exists){
              send404(res);
              return;
          };

           //finally stream the file
           res.writeHead(200,{'content-type': mimeType});
           fs.createReadStream(filepath).pipe(res);


       });
   }else {
       send404(res);
   }
}).listen(3000);

console.log('server running on port 3000');