How to start and stop a time in timer control using c sharp?

How to start and stop a time in timer control using c sharp?



EX: I have start & stop button in my form.

I need result like this... 

The timer has to start counting the time  from 00:00:00 if i click the start button

and 
 
if i click the stop button at time =00:02:35 ,the timer has to stop counting the time

and if i again click the start button ,it will  start counting the time from 00:02:36......How?

and also how to find the duration between start and stop ?