create a unique Random integer

Hi there,
I am trying to create a UID that is unique within my SQL Server. There are many users accessing the Server in seperate databases, but then I want to combine all the data from these tables, keeping the ID from each one as a primary key.

I have written the following function, but when i call it as a default value for a field, it does not produce a unique number.

CREATE FUNCTION GETNEXTID(@.CURDATE DATETIME)
RETURNS BIGINT
AS
BEGIN
RETURN (SELECT CAST(
CAST(DATEPART(YY,@.CURDATE) AS VARCHAR) +
RIGHT('0' + CAST(DATEPART(M,@.CURDATE) AS VARCHAR),2) +
RIGHT('0' + CAST(DATEPART(D,@.CURDATE) AS VARCHAR),2) +
RIGHT('0' + CAST(DATEPART(HH,@.CURDATE) AS VARCHAR),2) +
RIGHT('0' + CAST(DATEPART(SS,@.CURDATE) AS VARCHAR),2) +
RIGHT('00' + CAST(DATEPART(MS,@.CURDATE) AS VARCHAR),3) AS BIGINT))
END

Can anyone help?I would create a table as follows:

Create Table DatabaseId
(
DBId Int Identity,
DBName vachar (40) NOT NULL
)

When you import data from the different databases, prefix your unique identifier with DBId. That should give you an unique number across the DB's.|||Take a look at newid()