Hello.  In a survey we are wanting to get a customer's name and EITHER their phone number or e-mail address.  So all of our submissions should be either [ name + phone number ] or [ name + e-mail address ].

We have made the name field required, but we do not want to require the phone number field because some people may want to use their e-mail address instead (which is OK).  And we do not want to require the e-mail address field because some people may prefer to give us their phone number instead (which is OK).

The question is, is there anyway to require that one of those two fields must be filled out? 

Thanks much :)