ถามเรื่องการ Custom ปุ่ม Login ของ facebook ครับจะเปลี่ยน ปุ่มยังไงครับ

<a href="#" onclick="fb_login();"><img src="images/fb_login_awesome.jpg" border="0" alt=""></a>

window.fbAsyncInit = function() {
    FB.init({
        appId   : 'YOUR_APP_ID',
        oauth   : true,
        status  : true, // check login status
        cookie  : true, // enable cookies to allow the server to access the session
        xfbml   : true // parse XFBML
    });

  };

function fb_login(){
    FB.login(function(response) {

        if (response.authResponse) {
            console.log('Welcome!  Fetching your information.... ');
            //console.log(response); // dump complete info
            access_token = response.authResponse.accessToken; //get access token
            user_id = response.authResponse.userID; //get FB UID

            FB.api('/me', function(response) {
                user_email = response.email; //get user email
          // you can store this data into your database             
            });

        } else {
            //user hit cancel button
            console.log('User cancelled login or did not fully authorize.');

        }
    }, {
        scope: 'publish_stream,email'
    });
}
(function() {
    var e = document.createElement('script');
    e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js';
    e.async = true;
    document.getElementById('fb-root').appendChild(e);
}());