Made the IE frameElement check more explicit. Fixes #3880.

diff --git a/src/event.js b/src/event.js
index 08deb8b..e46e108 100644 (file)
--- a/src/event.js
+++ b/src/event.js
@@ -638,7 +638,7 @@ function bindReady(){
 
                // If IE and not an iframe
                // continually check to see if the document is ready
-               if ( document.documentElement.doScroll && !window.frameElement ) (function(){
+               if ( document.documentElement.doScroll && typeof window.frameElement === "undefined" ) (function(){
                        if ( jQuery.isReady ) return;
 
                        try {