Bug 136027 [Smoke]the report with a gounp can not preview
Description: the report with a gounp can not preview Steps to reproduce: 1. new a datasource and a dataset 2. drag the dataset to the layout 3. Add a group on the table. save and preview. Actual result: "Error happened while running the report" is appeared.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/GroupDialog.java
} );
		enableIntervalRangeAndBase( false );
	}
	/**
	 * Enable the interval range and base right after refreshing the interval
	 * type
	 * 
	 */
	private void enableIntervalRangeAndBase( boolean bool )
	{
		intervalRange.setEnabled( bool );
		intervalBaseButton.setEnabled( bool );
		intervalBaseText.setEnabled( bool );
	}
	public void elementChanged( DesignElementHandle focus, NotificationEvent ev )
	{
		if ( ev instanceof PropertyEvent )
		{
			if ( GroupHandle.BOUND_DATA_COLUMNS_PROP.equals( ( (PropertyEvent) ev ).getPropertyName( ) ) )
			{
				refreshColumnList( );
			}
		}
	}
	public boolean close( )
	{
		inputGroup.removeListener( this );
		return super.close( );
	}
}