Prism/WPF/Silverlight - setting ItemsControl height and width to full view using DockPanel style

Prism/WPF/Silverlight - setting ItemsControl height and width to full view using DockPanel style:


Figure 2 is the MainRegionTopContentBottom view that Prism will inject three views into (top, content and bottom). When the view is inserted into the MainRegion ItemsControl of figure 1 below the MainRegionTopContentBottom view is compressed vertically - we want it to fill the entire MainWindow.


Figure 1.