Rolevalue function in cognos

[sg]

Hi,

I need to use rolevalue function . I tried giving the below code,

rolevalue('_memberSet',Caption([Sales Region Name]))=[Query1].[Sales Region]

it throws the error. I'm new to MDX in cognos. Please let me know the exact code if anybody has used this function.

it throws error as below:

ERROR: Invalid Correation from value datatype to 'member set, member, heirarchy'

Thanks in Advance.

Thanks,
Sg