[jQuery] Unexpected call to method or property access + Jquery

[Rajeev]

        HI, I have a sidebar application which is using Jquery. In IE, there
is one error (Unexpected call to method or property access) occurs
while appending messages. In Firefox its working fine. The problem is
with the line;   join_message_jq.append(body_elem);


Here is the full code.
var room_avatar = '/avatar-service/lookup/?
sha1=f2f8ab835b10d66f9233518d1047f3014b3857cf';
var join_message_ar = ["<message from='"+nick+"'
to='4...@dev.trophyim.com/3' id='1' type='groupchat'><x
xmlns='jabber:x:event'><composing/></x></message>"];
            var join_message_jq = J(join_message_ar.join(""));
            var body_elem = document.createElement("body");
            var body_text = document.createTextNode("/me has "+status+" the
room.");
            body_elem.appendChild(body_text);

            join_message_jq.append(body_elem);
            Application.messageView().displayMessage(nick,
                                             room_avatar,
                                             join_message_jq.get(0),
                                             false);


Thanks Rajeev.