- for (var idx = 0; idx < this.registeredEvents_.length; idx++) {
- var reg = this.registeredEvents_[idx];
- Dygraph.removeEvent(reg.elem, reg.type, reg.fn);
+ if (this.registeredEvents_) {
+ for (var idx = 0; idx < this.registeredEvents_.length; idx++) {
+ var reg = this.registeredEvents_[idx];
+ Dygraph.removeEvent(reg.elem, reg.type, reg.fn);
+ }