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.
You should not use getElementById method here. Just use event.target during handling the event.
'students' property of classes objects hold an array of 'id' values (your 'item' variable): a number referering to the 'id' property of the students objects listed in the array of students object given as second argument... you should search and find inside the object with the related 'id' property, not acccess the 'students' array directly with it (this is not an index).