T-SQL (SS2K8) :: Finding Total Execution Time?

I have a SP SPone. i have optimized that and kept it as SPone_Optimized. i would like to test the both SP's execution time to find out how best the optimized one fares.

i planned to test it as follows

declare @starttime datetime,@endtime datetime
declare @count int=0
select @starttime=getdate()
while(@i<10000)
begin
execute SPone_optimized @param='value1'
end
select @endtime=getdate()
select datediff(ms,@stattime,@endtime) 'total_exec_time'

----- for the SP that is before optimize

declare @starttime datetime,@endtime datetime
declare @count int=0
select @starttime=getdate()
while(@i<10000)
begin
execute SPone @param='value1'
end
select @endtime=getdate()
select datediff(ms,@stattime,@endtime) 'total_exec_time'