"Select All" and "Clear All" buttons

I think it would be a great addition to the "Refine Results" dialog in the Silverlight Viewer to include a Select All and Clear All button.  If I have a lot of features selected from different layers, this list can grow rather large.  If the user wants just one layer, this can mean a lot of mouse clicks to isolate those features.

In general, this idea could be expanded to any situation in a viewer or administrator where a large number of items could need to be selected/unselected.

Dave