# sets unless $formdata->{redirect} is 
         # a) undefined b) "" or c) 0
$$redirect = $formdata->{redirect} if $formdata->{required};

         # this sets it only if $formdata->{redirect} is defined
         # ($formdata->{redirect} may be "" or 0 if already
         # initialized to that value)
$$redirect = $formdata->{redirect} if defined($formdata->{required};