The LinkedComboContainers makes it easy to chain together a set of comboboxes to come to a final result. A common example would be cars Make -> Model -> Trim.
The ComboBoxes can use any type of Ext.data.Store as a data source.
This means your data can be XML, JSON, arrays or any other supported format. It can be loaded using Ajax, JSONP or locally.
The example is not minified so it is readable. See linkedcombos.js.
The user extension is also not minified so it is readable. See LinkedComboContainer.js.