document.body.addEventListener("click",function(e){
	if(e.target.matches('#u_0_2')){
			alert();
	}
});

var parametrs = {
    appId: 1.....1,
    autoLogAppEvents: true,
    status : true, // check login status
    cookie : true, // enable cookies to allow the server to access the session
    xfbml  : true,  // parse XFBML
    version: 'v2.9' // or v2.1, v2.2, v2.3, ...
};
window.fbAsyncInit = function () {
    FB.init(parametrs);
    FB.Event.subscribe('edge.create', function (response) {
        alert('Liked');
        });
    }
    );
    FB.Event.subscribe('edge.remove', function (response) {
        alert('DisLiked')
    });
};
 
(function (d, s, id) {
    var js, fjs = d.getElementsByTagName(s)[0];
    if (d.getElementById(id))
        return;
    js = d.createElement(s);
    js.id = id;
    js.src = "//connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.7";
    fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));

<div id="fb-root"></div><div class="fb-like" data-href="https://www.facebook.com/testpage" data-layout="standard" data-action="like" data-size="small" data-show-faces="true"></div>