How to use custom css, html and js code into sencha touch

[maykelljob]

Hi, i'm new to sencha touch and everything i have seem so now is very interesting, but i tried to acomplished a task that have been imposible to me, so i need your help. I have a very little an simple piece of javascript and html that allow to create an html5 canvas and put a character on it. Now what a want is to insert that canvas usind the same code i allredy have into a tab area of sencha touch tab panel. But for reasons i don't know it doesn't work when i do that.
Can anybody give me a way to reuse my old javascript code into sencha touch?
Can anybody give me a way to incorporate and html5 canvas into a sencha touch movile app?
There is any way to use external css and js files into sencha touch?

Thank you very much.

[mitchellsimoens]

If you use Sencha Command to create your app, then you can add js and css in the app.json file to be loaded

[maykelljob]

Hi mitchellsimoens, thank you for your replay, it was very usefull, but i need a little more details. Can you bring me width a piece of code that do some like the situation a described in my first post?
Thank you very much.