[Zope] dtml syntax question

If I have a form field name of "oname:required", in order to allow zope to force an entry in that field, how can I access the value of that field from javascript. The normal form.fieldname.value doesn't work, since it would look like 'form.oname:required.value' and javascript barfs on that. There must be a solution to this, anyone know what it is? --sam