my @countries = do {
    my $fh;
    open($fh => "countries.txt")
     ? map { /(.*):(.*)/ ? $1 : () } <$fh>
     : ();
};

my $dropdown = make_dropdown("dropdown", @countries);
my $another  = make_dropdown("another",  @countries);

sub make_dropdown {
    my ($form_name, @countries) = @_;
    
    ## generate and return a dropdown with <select name="$form_name">
}