sub _load_xls ($) {
    my ($fname) = shift;
    return undef unless (-e $fname);
    my ($parse) = Spreadsheet::ParseExcel->new();
    my ($excel) = $parse->Parse($fname);
    my (%data);
    for (my $sheetcount = 0; $sheetcount < $excel->{SheetCount}; $sheetcount++) {
        my ($sheet) = $excel->{Worksheet}[$sheetcount];
        my (@fields, @data);
        for (my $field = $sheet->{MinCol}; defined $sheet->{MinCol} && $field <= $sheet->{MaxCol}; $field++) {
            my ($cell) = $sheet->{Cells}[$sheet->{MinRow}][$field];
            push (@fields, $cell->Value) if ($cell);
        };
        for (my $row = $sheet->{MinRow} + 1; defined $sheet->{MinRow} && $row <= $sheet->{MaxRow}; $row++) {
            my (%item);
            for (my $col = $sheet->{MinCol}; defined $sheet->{MinCol} && $col <= $sheet->{MaxCol}; $col++) {
                my ($cell) = $sheet->{Cells}[$row][$col];
                $item{$fields[$col - $sheet->{MinCol}]} = $cell->Value if ($cell);
            };
            push (@data, \%item);
        };
        $data{$sheet->{Name}} = {
            'fields'    =>  \@fields,
            'data'      =>  \@data,
        };
    };
    return (\%data);
};