code: function OpenFileCB (err, fd) {
          if (err) {
              response.setHeader('Content-Type','text/html');
              response.writeHead(404, err.toString("utf8"));
              response.write("Hoops:" +  err );
              response.end();
              return;
          }
          fs.fstat(fd, function(err,stats){
              // get file size and allocate buffer to read it
              var buffer = new Buffer (stats.size);
              fs.read (fd, buffer,0,buffer.length,0,ReadFileCB);
          });
      }
docs: open file and check if its supported