Wifi Module not found ?

In fact I tried different code like :

Serial2.setup(115200, { rx: A3, tx : A2 });
var wifi = require("ESP8266WiFi_0v25").connect(Seri­al2, function(err) {
  //                ^^^^^^^^^^^^^^^^
  //                Use ESP8266WiFi here (and 9600 baud) if you have an ESP8266 with firmware older than 0.25
  if (err) throw err;
  wifi.reset(function(err) {
    if (err) throw err;
    console.log("Connecting to WiFi");
    wifi.connect("WiFi_Name","WPA2_Key", function(err) {
      if (err) throw err;
      console.log("Connected");
      // Now you can do something, like an HTTP request
      require("http").get("http://www.pur3.co.­uk/hello.txt", function(res) {
        console.log("Response: ",res);
        res.on('data', function(d) {
          console.log("--->"+d);
        });
      });
    });
  });
});

return http and NetworkJS modules not found

>var wifi = require("Wifi");
=function () { [native code] }
>wifi.connect("my-ssid", {password: "my-password"},
   function(err){if(err)console.log(err);else console.log("connected!");})
=undefined

return Wifi module not found.

I flashed it with esptool, and I am trying to communicate with my esp8266 using Chrome web IDE.