better to rewrite the stored procedure like below:
CREATE PROCEDURE smpl
@roomno VARCHAR(20),
@ondate DATETIME,
@offdate DATETIME
AS
BEGIN
SELECT roomno,
roomno,
offdate
FROM [sample] s
WHERE s.roomno = @roomno
AND s.ondate = @ondate
AND s.offdate = @offdate
END
Use this stored procedure as the data source of crystal report and follow the link below to pass parameter from C#.
Crystal Report Filtering Using Selection Parameters[
^]