FB.XdComm is undefined javascript facebook

Here's the code which I am using to show the compose dialog box from facebook

  
var iframeDom=FB.XdComm.Server.singleton.createNamedHiddenIFrame('dialogContent','','fb_permission_iframe',null);
var myDialog=new FB.UI.PopupDialog('Title',iframeDom,true,false).show();
var userId = "user_id";
iframeDom.src=FBIntern.Utility.getFacebookUrl('www')+'inbox/'+'?compose&id='+userId+'&v='+FB.Facebook.version;//or any link that has ur dialog content..
myDialog.show();

I have also called FB.Init as well before calling the above code. I am getting FB.XdComm as undefined

I have also referenced h开发者_JAVA技巧ttp://connect.facebook.net/en_US/all.js under by body tag inside script tag.

Can anyone tell me what's missing

The code seems outdated, these things are no longer part of the Facebook API. You probably want to use the FB.ui method.