phantonjs node js screenshot of a website

gistfile1.js

var phantom = require('phantom');
var website_name = "amazon.in";

var takeScreenShot = function(website_name) {
    phantom.create(function(ph) {
        ph.createPage(function(page) {
            page.open("http://" + website_name, function(status) {
                if (status === "success") {
                    page.render("./images/"+website_name + '.png');
                }
                ph.exit();

            });
        });
    });
}

takeScreenShot(website_name);