I'm working on an application which will be using some data entry forms which get dynamically generated based on some selections made by the user. In the simple case, imagine a two panel app, where the left side is a collection of combo boxes, checkboxes, etc. and the right side is a form panel. When the user makes selections on the left and hits 'apply', the right panel needs to display a new set of data entry elements.

We are using a web service which takes a set of parameters and returns an array of Ext elements which comprise the new data. Conceptually what I would like to do is replace the 'items' collection of a FormPanel with a new Items collection and recompute the layout, but that doesn't work. Am I overlooking a simpler way to accomplish this task?