Report parameter and filtering

My report has a parameter that is used for a filter in one of my data set.
What I â'd like to do is to say if that parameter is not blank then use it
To filter data otherwise show everything. Is that possible?If you want to perform filtering in a query:
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=uOX2NreOEHA.2780%40TK2MSFTNGP09.phx.gbl
--
This posting is provided "AS IS" with no warranties, and confers no rights.
"Mark" <Mark@.discussions.microsoft.com> wrote in message
news:D1B71526-C984-4DE2-883F-040105BAB845@.microsoft.com...
> My report has a parameter that is used for a filter in one of my data set.
> What I 'd like to do is to say if that parameter is not blank then use it
> To filter data otherwise show everything. Is that possible?
>