Javascript Verifyer Tool

I've done i bit of searching and can't find a tool like this anywhere.

Basically what I'm looking for is a tool where I specify a url and the tool will go and test all the javascript within the page. It will then tell me which browers the code will work on and pinpoint areas where cross-browser compatability is broken.

Anyone ever seen a tool like this?

Thanks

I haven't seen anything like that, but I think there is a JS validator in Mozilla, haven't really used it much though so I can't tell you much about it.

Do you mean JavaScript itself or HTML-DOM?
JavaScript is pretty much the same in different browsers. (Of course only newer browsers will support things like try...catch, etc.). But almost every browser has a different implementation of the HTML-DOM. This causes much problems when it comes to cross-platform scripting.
The only "tool" I know about is called "alert". I'm using alert-boxes quite often when debugging JavaScript code. Browsers like IE and Mozilla will alert you when there's something wrong in the javascript. (Most of the time an object, property or method doesn't exist. -> HTML DOM-problems)