fix for bug where calling blur with empty focus stack would push an undefined element onto the stack

build/js/ox.ui.js

@@ -411,7 +411,7 @@ requires
             blur: function(id) {
                 Ox.print('BLUR', id, stack)
                 var index = stack.indexOf(id);
-                if (index == stack.length - 1) {
+                if (index > -1 && index == stack.length - 1) {
                     stack.length == 1 ? stack.pop() :
                             stack.splice(stack.length - 2, 0, stack.pop());
                     // fix later: Ox.Event.unbindKeyboard($elements[id].options('id'));