javascript innerHTML adding instead of replacing

Answer 1

What jcomeau_ictx suggested is an inefficient way of editing the innerHTML. Check Ben cherry's PPT http://www.bcherry.net/talks/js-better-faster

The correct way will be detaching the element and making changes to it and then appending it back to the parent node. Use https://gist.github.com/cowboy/938767 Native javascript from this gist to detach element.