Fido U2F client side javascript source code

I'm looking for a JavaScript source code (client side) to make communication between Fido U2F token and Google Chrome (Version 41.0.2272.89 m).

Please help me

Here is an example to getting the Token response for registration using Yubico u2f-api file

var RegistrationData = {"challenge":"dG7vN-E440ZnJaKQ7Ynq8AemLHziJfKrBpIBi5OET_0",
                     "appId":"https://localhost:8443",
                     "version":"U2F_V2"};

window.u2f.register([RegistrationData], [],
  function(data) {if(data.errorCode) {
        alert("U2F failed with error: " + data.errorCode);
        return;
    }
    alert(JSON.stringify(data));
}); 

you've to include the u2f-api.js and use an Https server