The first two checks are unnecessary

		where  (@StartTime between begintime and endtime
	        	or dateadd(mi,@ilength,@StartTime) between begintime and endtime)
	        	and iscancelled=0 and roomid = @RoomID 

>I have this function that checks for conflicts, but it is not very fast, does anyone have a better sugguestion on how to code this? If I take out the or clauses, it performs fast, but I'm afraid it could allow for conflicts without the other checks.
>
>
>

>CREATE FUNCTION ctFun_RoomConflictA  (@RoomID int, @iLength int, @StartTime datetime )
>RETURNS int as
>BEGIN
>     Declare @returnValue int
>        select  @returnValue=
>	  (select count(meetingnumber) from dbo.meetings
>		where (begintime between @StartTime and dateadd(mi,@iLength,@StartTime)
>	        or     endtime   between @StartTime and dateadd(mi,@iLength,@StartTime)
>	        	or @StartTime between begintime and endtime
>	        	or dateadd(mi,@ilength,@StartTime) between begintime and endtime)
>	        	and iscancelled=0 and roomid = @RoomID )
>      return (@returnValue)
>END
>

>