Problem tracking what javascript is causing jQuery UI error in firebug

So I am getting the following error in firebug开发者_开发问答 regarding jQuery UI. It would be as simple if it was a matter of a process-of-elimination on the JS on the page, but there is allot of JS as well as some on the page and some on the site.master.

ERROR

(this.uiDialogTitlebarCloseText = c("<span/>"))
  .addClass("ui-icon ui-icon-closethick").text(m.closeText).appendTo 
    is not a function

Is there a way in Firebug to see what javascript is the initial caller?

---

Well your problem is likely that m.closeText is null. If you pass a null argument to text() it will actually return the text of the element, and not set the text to null.

I'm not sure about how to debug it though.

EDIT: The error is thrown because if text(null) returns a string, than you'll be saying string.appentTo rather than $().appendTo.