Dán code này vào nơi muốn hiển thị nha....

<iframe src="//www.facebook.com/plugins/like.php?href=http://facebook.com/https://www.facebook.com/pages/H%E1%BB%99i-Th%C3%ADch-%C4%90%E1%BB%8Dc-Truy%E1%BB%87n-Online/503848553085907&width=240&layout=standard&action=like&show_faces=false&share=true&height=80" scrolling="no" frameborder="0" style="border:none;overflow:hidden;width:240px;height:27px;"allowTransparency="true"></iframe>