I have a scalar valued function and it is complied successfully. But when i am trying to call that function it throwing error!! Check this sample code

```
CREATE FUNCTION Fn_lastupdate(@ID INT, 
                              @b  INT) 
returns DATETIME 
AS 
  BEGIN 
      DECLARE @lastupdate DATETIME 

      SELECT TOP 1 @lastupdate = lastupdate 
      FROM   clientlog 
      WHERE  id = @ID 

      RETURN @lastupdate 
  END

```

I am calling lyk 

```
select fn_lastupdate(@id)

```

but am getting error as 

```
 fn_lastupdate not recognized

```