The URL you give is totally wrong. I assume you meant http://demos.kendoui.com/web/grid/editing-popup.html
but this basically doesn't use Html Helpers and instead does the entire operation in a .html file.
It would be better if the Html helpers could be used because they have all the advantages of intellisense, plus they know all about the fields and can make use of the Data Annotation Attributes. But as it is, we have to repeat all that information which is time consuming and error prone.