sub main {
    my $err = "";
    my $name = param("name");
    my $phone = param("phone");
    my $postal = param("postal");

    if ($name !~ /[A-Za-z- ]*/) {
        $err += div("Name must only contain letters, hyphens, and spaces");
    }
    if ($phone !~ /[0-9]{3}-[0-9]{3}-[0-9]{4}/) {
        $err += div("Phone number must be in the format NNN-NNN-NNNN");
    }
    if ($postal !~ /[A-Z][0-9][A-Z] [0-9][A-Z][0-9]/) {
        $err += div("Postal code must be in the format A1A 1A1");
    }