You're welcome.

>
>In so many words - Thank's!
>
>>The ELSE in the first example is never executed when SET ANSI_NULLS OFF.

>>SELECT #Temp.*,
>>   CASE WHEN (#Temp.S1 = #Temp.S2) OR COALESCE(#Temp.S1,#Temp.S2) IS  NULL THEN 1
>>        ELSE 2  END AS S3 From #Temp
>>