Build a Contacts Manager Using Backbone.js: Part 4 In part four of this series, we saw how easy it is to add and remove models from our collection, and keep the page updated in sync with the changes. In this part, we're going to look at editing existing model data. Getting Started We'll start out by adding another simple button to the template, which will enable editing of its data: As we are adding this button to our existing template, we can also add an entirely new template that can be used to render an editable form in which the model data can be changed. Boogie: An Intermediate Verification Language Boogie is an intermediate verification language, intended as a layer on which to build program verifiers for other languages. Several program verifiers have been built in this way, including the VCC and HAVOC verifiers for C and the verifiers for Dafny, Chalice, and Spec#. A previous version of the language was called BoogiePL. The current language (version 2) is currently known as just Boogie, which is also the name of the verification tool that takes Boogie programs as input. The Boogie research project is being developed primarily in the RiSE group at Microsoft Research in Redmond.