use strict;
use Spreadsheet::WriteExcel;
{
    my $workbook = Spreadsheet::WriteExcel->new("one.xls");
    my $north = $workbook->addworksheet("one");
    my $format = $workbook->addformat();
    $format->set_bold();
    $north->write(0, 0, "One -- this should be bold", $format);
}
{
    my $workbook = Spreadsheet::WriteExcel->new("two.xls");
    my $north = $workbook->addworksheet("two");
    my $format = $workbook->addformat();
    $format->set_bold();
    $north->write(0, 0, "Two -- this too should be bold", $format);
}