Bug 200312 Chart Variables are still in the bottom right pane when select other categories [13]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ExpressionBuilder.java
{
				childrenList.addAll( getChildren( children[i] ) );
			}
			return childrenList;
		}
		public void dispose( )
		{
		}
		public void inputChanged( Viewer viewer, Object oldInput,
				Object newInput )
		{
			if ( viewer == subCategoryTable )
			{
				functionTable.setInput( null );
			}
		}
	}
	private ISelectionChangedListener selectionListener = new ISelectionChangedListener( ) {
		public void selectionChanged( SelectionChangedEvent event )
		{
			IStructuredSelection selection = (IStructuredSelection) event.getSelection( );
			if ( selection.isEmpty( ) )
			{
				return;
			}
			Viewer target = null;
			if ( event.getSource( ) == categoryTable )
			{
				target = subCategoryTable;
			}