I'm developing a site which has a basic contact form.

I'm trying to validate this form instantly using this tutorial: http://tetlaw.id.au/view/javascript/...eld-validation

I'm using Firefox with the Firebug add-on and whenever I load my test page with the contact form, I receive this error message in Firebug:

$(form).getElementsByTagName is not a function
getElements([])prototype.js (line 1799)
initialize("contact_form", Object immediate=true)validation.js (line 88)
I've got this to work before on other sites, but for some reason it's not working on this site and I just don't know why and I don't understand what the error is telling me.

The URL to the test page is: http://test.ksba.org/index.php/static/ask-ksba

Can anyone explain what's going on and maybe what I should to do fix it?