Hi, In order to make full use the Facebook like button, I am trying to switching from iframe-based like button to js-based like button. url: http://www.dealsvista.com Everything works fine for a user who is logged into Facebook. However, for a user who is not logged into Facebook, when he clicks the like button, there is a error in the popup window. Could someone point me to the right direction? I am really new to Facebook api and have no idea what is going on? Do I have to implement connect at the same time? Do I have to set up the connect call back url in my apps?