MDX: Cummulative Sum

Some sample query for cummulative sum in MDX

WITH    SET [Set Of Months] AS     Descendants     (       [Date].[Calendar].[Calendar Year].&[2003]      ,[Date].[Calendar].[Month]      ,SELF     )   MEMBER [Measures].[Incremental Sum] AS     Sum     (       Head       (         [Set Of Months]        ,Rank         (           [Date].[Calendar].CurrentMember          ,[Set Of Months]         )       )      ,[Measures].[Internet Sales Amount]     ) SELECT    {     [Measures].[Internet Sales Amount]    ,[Measures].[Incremental Sum]   } ON 0  ,[Set Of Months] ON 1FROM [Adventure Works];