Highlighting the right margin

[fortepianissimo]

I've been trying to make an .el file I downloaded to work so I can see
where the right margin starts to avoid coding long lines.

The file is highlight-beyond-fill-column.el, and I have this line in my
.emacs

(require 'highlight-beyond-fill-column)


But after restarting emacs (22.0.50 on Mac OS X), hitting M-X and then
trying to invoke the function highlight-beyond-fill-column, I couldn't
find the function at all.

I'm almost completely ignorant on elisp - could someone show me some
voodoo magic that I need to put into my .emacs file to make this work?

Thanks a lot!