Bug 113938 Report is marked dirty when open/close cascading parameter dialog without doing any operation on it
description: Report is marked dirty when open/close cascading parameter dialog without doing any operation on it steps to reproduce: 1.new a cascading parameter group 2.save the reprot 3.double click the cascading parameter to bring out edit box 4.click OK to close edit box actual result: Report has been marked dirty expected result: No dirty marked for that no operations done in edit parameter dialog
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ExpressionProvider.java
else if ( element instanceof DataSetItemModel
				|| element instanceof ParameterHandle )
		{
			return DEUtil.getExpression( element );
		}
		return null;
	}
	private static Image getIconImage( String id )
	{
		return ReportPlatformUIImages.getImage( id );
	}
	private List getClassList( boolean isNative )
	{
		List list = DesignEngine.getMetaDataDictionary( ).getClasses( );
		ArrayList resultList = new ArrayList( );
		for ( Iterator iter = list.iterator( ); iter.hasNext( ); )
		{
			IClassInfo classInfo = (IClassInfo) iter.next( );
			if ( classInfo.isNative( ) == isNative )
			{
				resultList.add( classInfo );
			}
		}
		return resultList;
	}
	/**
	 * Adds a filter for this expression builder.
	 * 
	 * @param filter
	 *            the filter to add