return "unknown cust_main.custnum: ". $self->custnum
unless $self->invnum
|| qsearchs( 'cust_main', { 'custnum' => $self->custnum } );
return "unknown cust_main.custnum: ". $self->custnum
unless $self->invnum
|| qsearchs( 'cust_main', { 'custnum' => $self->custnum } );