Use Timer class and ElapsedEventHandler delegate.
The sample code looks like below
double timeout = 900000;
if (time != null && time.Length > 0)
timeout = Convert.ToInt64(time);
System.Timers.Timer timer = new System.Timers.Timer();
timer.Interval = timeout;
timer.AutoReset = true;
timer.Elapsed += new System.Timers.ElapsedEventHandler(OnTimeReached);
timer.Start();
Please change the timeout value accoring to ur convenience.It is in second.