When is it Safe to Modify the DOM?

This is a pretty important question when in comes to DOM programming.  Start manipulating the DOM to early and bad things happen .  Do it too late and the users may see that annoying flicker .   So what’s the best technique for figuring this out?  Well, I was curious about this myself so I took a look at how some of the popular Ajax libraries ( jQuery , MooTools , YUI , Prototype and ASP.NET AJAX ) are doing this.  Here is what I found out ...   You don’t need to wait for window.onload ... Its definitely safe to muck with the DOM in the window’s onload event, but there is really no need to wait that long.  The onload event doesn’t fire until the entire page has loaded (DOM plus images) and often that ends up being too late.  The user ends up seeing the page in potentially 3 different states: DOM without images, DOM with images, and finally the DOM with images and what ever changes your script has applied.  There is no reason why your ...