next 30 days or all values

Hi,
I have a dataset and I need to be able to filter that data based on
Completion Date.
I have created a user parameter is SSRS with the following values:
0 = All Dates
1 = Next 30 days
I am trying to filter my dataset but I don't know how to filter this
based on my user parameter.
Help!
JasonI figured it out
if the user selects "All" then Parameter!Completion.Value = 0
if the user selects "Next 30 Days" then Parameter!Completion.Value = 1
so my filter looks like:
=iif (Parameters!Completion.Value=1, date.Today.AddDays(30),
date.MaxValue)