Backbone写入JSON

Here is a link to the code on github

https://github.com/dkhuntrods/Wedding-Seating-Planner-Prototype

I have a problem with writing the change of states. When something is moved

on canvas all, changes should be saved to json files. Here is a screen capture of the problem

Basically, I think it cannot locate tables.json/table1 because there is no such

file. However, I cannot seem to understand the code.