hi I find that in many cases I need my background tasks to be executed in sequence. Ie, I need background task-b to start right after background task-a has properly started. So far I haven't found a good way to do it. I used task-a & sleep 2; task-b & but that 'sleep 2' has changed to 'sleep 5' and still sometimes task-b starts before task-a. I can raise the wait time, but it means that task-b would normally start too late... Any good way? thanks