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
if ( inputArray.length == 2
							&& inputArray[1] instanceof ReportItemHandle )
					{
						ColumnBindingDialog dialog = new ColumnBindingDialog( );
						dialog.setInput( (ReportItemHandle) inputArray[1] );
						if ( dialog.open( ) == Window.OK )
						{
							functionTable.refresh( );
						}
						return;
					}
				}
				String insertText = provider.getInsertText( selection.getFirstElement( ) );
				if ( insertText != null )
				{
					insertText( insertText );
				}
				return;
			}
		}
	};
	private Composite buttonBar;
	private TableViewer categoryTable, functionTable;
	private TreeViewer subCategoryTable;
	private IExpressionProvider provider;
	private SourceViewer sourceViewer;
	private String expression = null;
	private Label messageLine;
	private String title;
	/**