Many thanks.

I think it is a good soluton too.

Someone advice me that is it works the same...

IIF(ISEMPTY([Measures].[Sales Amount] )

,NULL

,SUM ({ [Company].[All Company].[COMET]},[Measures].[Sales Amount]) )

,NON_EMPTY_BEHAVIOR = {[Measures].[Sales Amount]}

Thanks a lot.

Sorry but even if i use SSAS 2008 R2 from a long time (5 years) , i am not so good in MDX.

i HAVE TO IMPROVE MY knowledge.