sub print_html_header {
        my $self = shift;
        if ($self->style eq "excel") {
                my $filename = $self->new_excel_filename;
                $self->{r}->header_out('Content-Disposition'=>"attachment; filename=$filename")
        }
        my $content_type = ($self->style eq 'excel') ? 'application/vnd.ms-excel'
                : 'text/html'; 
        $self->{r}->send_http_header($content_type);
}