+my $new;
+my $error;
+if ( $hash{'bill'} != $old->bill # if the next bill date was changed
+ && $hash{'bill'} < time # to a date in the past
+ && ! $cgi->param('bill_areyousure') # and it wasn't confirmed
+ )
+{
+ $error = '_bill_areyousure';
+} else {
+ $new = new FS::cust_pkg \%hash;
+ $error = $new->replace($old);
+}