Codenstuff.com

Is it possible to fill in a form on another webpage with javascript on a page?
Example: http://www.kasteeltje.westsite.be
The button "Nieuwsbrief" pops up a form to fill in for subscribing to a newsletter. I want to make a facebookpage with html, just a form for the Subscribe to a newsletter. Can somebody help me out? or put me on the right path?

That website doesn't seem to load for me. Though it is possible to fill out HTML forms with JavaScript, it depends how the page is designed.

Oh sorry, misstyped the link,..
http://kasteeltje.westsite.be

I have read up a bit on the subject of cross-site scripting. It would appear you can't use a script on one site to access another, and this is a standard security measure in all browsers.