Optional Parameter In Sql Query

Hi All,

I have a stored proc which looks like this.

Create ....
(
@id int,
@ud int,
@td int=0
)

if @td=0
select bkah from asdf where id=@id and ud=@ud
else
select bkah from asdf where id=@id and ud=@ud and td=@td

---------------------------------
I am wondering if i could replace if condition with the following line

select bkah from asdf where id=@id and ud=@ud
and ( @td<>0 and td>@td )

IS sql server 2000 smart enough not to use the td>@td in the query if
@td is 0


Thanks all