async file appender in node js

var fs = require("fs");
/**
 * Asyncronous file appender in node js that allows you to easily append to a file
 * without doing it all once
 */
var Appender = function(filename) {
   var queue = Array();
   var isOpen = false;
   var curObj = this;

   /**
    * @param text - text to be written. 
    */
   this.write = function(text) {
      //store what needs to be written in a queue                                                                                                                         
      if(text) queue.push(text);

      //don't call open again if the queue is still being processed by a previous call to write
      if(!isOpen) {
         isOpen = true;

         //open the file for writing 
         fs.open(filename, 'a', 33206, function(err, fd) {
            if(err) throw err;

            var str = queue.shift();
            fs.write(fd, str, null , 'utf8', function(err, bytes) {
               if(err) throw err;
               sys.puts(bytes + ' bytes were written\n' + str);

               fs.close(fd, function() {
                  isOpen = false;
                  //recursive call to write until queue is empty
                  if(queue.length > 1) {
                     curObj.write(null);
                  }
               });
            });
         });
      }
   }
}