Thanks Sergey!,

With your code I found some stuff in BOL

"deleted and inserted are logical (conceptual) tables. They are structurally similar to the table on which the trigger is defined, that is, the table on which the user action is attempted, and hold the old values or new values of the rows that may be changed by the user action. For example, to retrieve all values in the deleted table, use:"

And create the following from yours:

CREATE TRIGGER SETDEFAULT ON dbo.ss_Description
FOR INSERT, UPDATE
AS
DECLARE @llDefault bit

IF UPDATE(lDefault) 
BEGIN
  SELECT @llDefault = lDefault  FROM Inserted 
  IF @llDefault = 1
    BEGIN
      UPDATE ss_Description SET lDefault = 0 
      WHERE lDefault = 1 AND cFilter = (SELECT cFilter FROM Inserted)
      AND ID <> (SELECT ID FROM Inserted)
    END  
END

The buzz word I was looking for is INSERTED (This is where my current record is stored)


>See sample working code below. It handles attempts to set multiple IsDefault to 1 and recursion.
>Table name is TestTr. I used column name 'IsDefault' because DEFAULT is reserved word.

IF EXISTS (SELECT name    FROM   sysobjects
>	   WHERE  name = N'trig_test' AND type = 'TR')
>    DROP TRIGGER trig_test
>GO
>CREATE TRIGGER trig_test
>ON dbo.TestTr
>FOR INSERT, UPDATE
>AS
>DECLARE @UpdateCount int
>IF UPDATE(IsDefault)
>BEGIN
>	SELECT @UpdateCount = COUNT(*) FROM Inserted
>		WHERE IsDefault > 0
>	IF @UpdateCount > 1
>	BEGIN
>		RAISERROR ('Only one item can be IsDefault', 16, 1)
>		ROLLBACK TRANSACTION
>	END ELSE
>	--
>	IF @UpdateCount = 1
>	BEGIN
>		UPDATE TestTr SET IsDefault = 0
>			WHERE IsDefault = 1
>				AND id <> (SELECT id FROM Inserted)
>	END
>END
>

>
>>
>>How would you solve this situation?
>

>>Table Test
>>
>>ID       DESCRIPTION   DEFAULT
>>1        Apple         0
>>2        Banana        0
>>3        Carrot        0
>>4        Citrus        1
>

>
>>When updating record ID = 1 (Apple) and assigning DEFAULT = 1
>>
>>I wanted an UPDATE trigger to reset all other records with DEFAULT = 1 (Citrus) Except the one I'm updating (Apple).