Multiple answers for parameters

[Big E]

I'm using ASP.Net and SQL Server.
On the form I have a QuestionId and a Community.
There is only one questionId and many communities. My sp has @QuestionId and
@CommunityId.
My result set should be show where @QuestionId = txtQuestionId and
@CommunityId = where all communities have the same questionId. How can I do
this? I need to force multiple parameter answers into one parameter?

Thanks.

Big E