Something like this will work for two text fields, ssn and passportNumber.
// form1.page1.ssn::exit - (JavaScript, client)
if (this.isNull && form1.page1.passportNumber.isNull) {
xfa.host.messageBox("You must enter either your SSN or passport number.","Required Fields");
}
// form1.page1.passportNumber::exit - (JavaScript, client)
if (this.isNull && form1.page1.ssn.isNull) {
xfa.host.messageBox("You must enter either your SSN or passport number.","Required Fields");
}
This code will not prevent form or data submission from occurring with either field filled, however, if form or data submission is included on the form.
Steve