Hi,

> 1. Can use <canvas> with innerhtml?

No. Canvases (from my initial understanding) are manipulated by
scripting, but not innerHTML.

> 2. 1Can I use innerhtml to add a new <canvas> element?
> (I'm thinking of having "layers" in my drawing application)

I would imagine so, and then using scripting to draw on you new canvas.

> 3. Can I put canvas inside a layer?(well...it worked on my computer
> somehow, but does all browsers support this?)

I think IE8 will support canveses (but from what I've seen on the short
time I've been on this list, perhaps not). Otherwise you'll want FF3 -
Opera and Safari seem buggy.

--
Richard Heyes
http://www.phpguru.org