+my @errors = ();
+
+push @errors, '_bill_areyousure'
+ 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
+
+push @errors, '_setup_areyousure'
+ if ! $hash{'setup'} && $old->setup # if the setup date was removed
+ && ! $cgi->param('setup_areyousure'); # and it wasn't confirmed
+
+push @errors, '_start'
+ if $hash{'start_date'} && !$old->start_date # if a start date was added
+ && $hash{'setup'}; # but there's a setup date