Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
Then your code is not correct, you're trying to read the length of something (null) that hasn't that property. You need to check what the value is first.
Would you mind reading the error..? And telling us what it is? :P
probably not a problem with the JavaScript code; it has 6,319 completions. if you have a specific question someone may be able to help you.