split screen game with html5

This seemed like the most relevant forum to post this:

I'm starting a game that will be two player split screen, and I want to know how to do it the most optimally.

My first thought was to use two canvas elements side by side, but it seems too sloppy; especially when dealing with things like a menu screen when there is no split screen showing.

I was wondering if there was maybe a built in way to deal with this, or if not what should the pseudo code roughly look like?

Thanks for reading