Using <ENTER> to Submit Form

I have read and tried out DENOnKeyDown and I can't figure it out. I've used the test.html file but it never pops up the "hello" window.

I uploaded the denonkeydown folder into my plugins directory, added the line into my fckconfig.js file.

It doesn't work for me in IE or Firefox?

Is this the only way? Is there a simpler solution?