>Metin,
>
>In SQL Server you can not create an index using a function. Use a date range when looking for a date, e.g.
>

>select * from myTable where DateField >=@Today and DateField < @Tomorrow
>

Thank you all,
I'll use Naomi's way. I use in first variable today 00:00 and second variable today 24:59:59 . I'm afraid of about performance in other ways. I'm not sure if sql server will use index with other ways...