- if ( !event.which && ((event.charCode || event.charCode === 0) ? event.charCode : event.keyCode) ) {
- event.which = event.charCode || event.keyCode;
+ if ( event.which == null && (event.charCode != null || event.charCode != null) ) {
+ event.which = event.charCode != null ? event.charCode : event.keyCode;