CREATE TABLE [dbo].[Fixtures](
[FixtureID] [int] IDENTITY(1,1) NOT NULL,
[KickOff] [datetime] NOT NULL,
[HomeTeamID] [int] NOT NULL,
[AwayTeamID] [int] NOT NULL,
[HomeTeamScore] [smallint] NULL,
[AwayTeamScore] [smallint] NULL
) ON [PRIMARY]

CREATE TABLE [dbo].[Predictions](
[PredictionID] [int] IDENTITY(1,1) NOT NULL,
[UserID] [int] NOT NULL,
[FixtureID] [int] NOT NULL,
[HomeTeamGoals] [smallint] NOT NULL CONSTRAINT
[DF_Predictions_HomeTeamGoals]  DEFAULT ((0)),
[AwayTeamGoals] [smallint] NOT NULL CONSTRAINT
[DF_Predictions_AwayTeamGoals]  DEFAULT ((0)),
[Points] [int] NULL,
[Submitted] [bit] NOT NULL CONSTRAINT [DF_Predictions_Submitted]  DEFAULT
((0))
) ON [PRIMARY]

When I add a new user, I want to be able to add the FixtureID and the new
UserID to the Predictions table for each existing Fixture.  So far, I've got
the following (which doesn't work):

CREATE PROCEDURE [dbo].[AddUser]
@UserName nvarchar(50),
@Password nvarchar(10),
@EmailAddress nvarchar(130)
AS
BEGIN
DECLARE @ID int
SET NOCOUNT ON;

INSERT INTO Users (UserName, Password, EmailAddress)
VALUES
(@UserName, @Password, @EmailAddress)
SET @ID = SCOPE_IDENTITY()
INSERT INTO Predictions (UserID, FixtureID) SELECT (SELECT USERID From
Users WHERE UserID = @ID), (SELECT FixtureID FROM Fixtures)
Return @ID
END

The subquery returns more than one value, which I'm told isn't allowed.  In
client-side code, I could select all the FixtureIDs and just interate
through them, inserting as I go, but I feel this is inefficient.  Or is it
my only real choice?

Thanks