Extend a small existing codeiginiter project with some drag&drop functionality.

A small existing project written in php using codeiginiter framework and a MySQL database needs to be extended: - Retrieve a list of items from a database (functionality already exists) and display them as checkbox list. - Retrieve another list of items and display them in a grid. - Drag one or more on the first items on an item of the grid. (Writes link between these items to the database). More information in the [login to view URL] file attached. Extra information can be given on request. It is important that the project is written using clean code, object oriented principles and is well documented so that other programmers can extend and modify it.