[Uncaught Error: Function "write" not found!] MQTT on ESP8266

Hi,
For some odd reason the code is as follows; Just playing around and bumped into the issue.
Is anyone else seeing this issue ? I am uploading directly to the ESP8266

var wifi = require("Wifi");

var server = "192.168.1.25";

var mqtt = require("MQTT").create(server);
mqtt.on('connected', function() {
  mqtt.subscribe("pcduino");
});

mqtt.on('publish', function (pub) {
  console.log("topic: "+pub.topic);
  console.log("message: "+pub.message);
});


wifi.stopAP();
wifi.disconnect(); 
wifi.scan(function(data){

  for(x in data)
  {
    console.log(data[x].ssid);
  }

  //wifi.connect("ABC", {password:"xyz"}, function(err){
  //  console.log("connected? err=", err, "info=", wifi.getIP());
  //});

  wifi.connect("Zain-E5577-0462", {password:"85887536"}, function(err){
    console.log("connected? err=", err, "info=", wifi.getIP());
    mqtt.connect({
      keep_alive: 60, // keep_alive[seconds]
      port: 1883, // port number
      clean_session: 1883, // port number
      username: "xyz", 
      password: "xyz", 
      protocol_name: "MQTT", // or MQIsdp, etc..
      protocol_level: 0, // protocol_level
    });
  });

});

Error As follows;

Uncaught Error: Function "write" not found!
 at line 1 col 35
....log("Client connected");b.write(a.mqttConnect(a.clie­nt_id))...
                              ^
in function "d" called from line 3 col 143
..."close")});a.client=b};b?d():b=requir­e("net").connect({host:...
                              ^
in function "connect" called from line 1 col 184
...me:'MQTT',protocol_level:0});
                              ^
in function called from system