This is an simple example to show you how to create a viewport in ExtJs4.
The Viewport renders itself to the document body, and automatically sizes itself to the size of the browser viewport and manages window resizing. There may only be one Viewport created in a page.
The Viewport does not provide scrolling, so child Panels within the Viewport should provide for scrolling if needed using the autoScroll config.
Unlike the panel component of Ext JS, Viewport does not have a tbar option. ...