sub hidden_field {
    my $counter = $cgi->param('field_1');

    if ( not defined $counter ) {
        $counter = 1;
    } else {
        $counter++;
    }

    print $cgi->hidden('field_1', $counter);

    return $counter;
}


my $count = hidden_field;

foreach ( 1 .. $count ) {
  #here is a seperate function that generates set of 3 text_area 
}