Sorry, I should use this instead of my last post:

CREATE PROCEDURE sp_MySearch

@p1 varchar(50),

@p2 varchar(50)

As

select * from t

where

isnull(c1, isnull(@p1,'')) like case when len(isnull(@p1,'')) =0 then isnull(c1, '') else '%'+@p1+'%' end and

isnull(c2, isnull(@p2,'')) like case when len(isnull(@p2,'')) =0 then isnull(c2, '') else '%'+@p2+'%' end