Mostra sempre lo stesso dato

[satifal]

Prova a cambiare così:

...
foreach ( $row1 AS $rows1 ) {
    echo('<form action="rassegnalibro.php" method="POST">');
    echo('<input type="hidden" name="mTS" value="'.$rows1['name_libro'].'" /><input type="submit" value="'.$rows1['name_libro'].'" accesskey="s" class="submit" />');
    echo('</form>');
}
...