Start Building Professional
Web Apps Today

To prevent sorting, due to click in checkbox which is appened in header column we stop event propaganation as you say, something to next var astr="A"; grid.setHeader(astr); But what if we have to write events on that checkbox,now?

The added code just block event propagation for parent elements, it will not block the events on checkbox element.
You can attach event handler by any possible way - by attachingEvent or by adding some custom code to existing onclick event.