Insert record and return Id in a SQL UDF??

Question

I need a user defined function to insert a new record and return the Id, is this possible and how do I do it?

I have tried creating a function with the insert statement but I am getting the following error:

Invalid use of the side-affecting operator 'INSERT' within a function.

I am using SQL server 2008.

UPDATE SQL:

CREATE FUNCTION dbo.GetNewBookingReference()

RETURNS int

AS

BEGIN

INSERT INTO BookingReference
(CreatedTime, CreatedByUserId)
VALUES
    (GETDATE()
    ,10)

RETURN @@IDENTITY

END

Thanks

Answer 1

insert into table1(name, age) values('xyz', 2);
select SCOPE_IDENTITY() as NewID;

Answer 2

In SQL Server, user-defined functions cannot change database state. You will have to use a stored procedure with an OUTPUT parameter.