What am I doing wrong with a parameter being passed in codebehind to a storped procedure, I get an error.

I get the error "Procedure or function 'ContactsSearch' expects parameter '@Param1', which was not supplied." when running the following code.  I have one parameter in the stored procedure, and I am feeding one parameter in, I dont' understand what is going on.
ALTER PROCEDURE [dbo].[ContactsSearch] ( @Param1 VARCHAR(25) ) AS SELECT * FROM Contacts SqlDataSourceListView.SelectCommand = "ContactsSearch" SqlDataSourceListView.SelectParameters.Clear() SqlDataSourceListView.SelectParameters.Add("Param1", "test")