gini aja deh

<table class="table table-hover table-bordered" cellspacing="0" width="100%">
            <form id="inputnilai" method="post" action="">
              <thead>
              <tr>
                <th style="width: 30px; text-align: center;" rowspan="2">No</th>
                <th style="width: 170px; text-align: center;" rowspan="2">Nama Lengkap</th>
                <th style="text-align: center;" colspan="6">Pengetahuan</th>
                <th style="width: 55px; text-align: center;" rowspan="2">N/A</th>
                <th style="text-align: center;" rowspan="2">Deskripsi</th>
                <th style="text-align: center;" rowspan="2">Action</th>
              </tr>
              <tr>
                  <th style="width: 55px; text-align: center;">N1</th>
                  <th style="width: 55px; text-align: center;">N2</th>
                  <th style="width:  55px; text-align: center;">N3</th>
                  <th style="width: 55px; text-align: center;">N4</th>
                  <th style="width: 55px; text-align: center;">N5</th>
                  <th style="width: 55px; text-align: center;">N6</th>
              </tr>
              </thead>
              <tbody>
              <?php $no=1; foreach ($siswa as $row) { ?>
              <tr>
              <input type="hidden" name="jenis" value="Pengetahuan">
              <input type="hidden" name="jadwal" value="<?php echo $row->id_jadwal;?>">
              <input type="hidden" name="siswa" value="<?php echo $row->id_siswa;?>">
                <td><?php echo $no++; ?></td>
                <td><?php echo $row->nama_siswa; ?></td>
                <td><input type="text"
data-siswaid="<?=$row->id_siswa;?>" data-col="n1"
name="data[<?php echo $row->id_siswa;?>]n1" style="width: 35px; text-align: center; padding: 0px;"></td>
                <td><input type="text"
data-siswaid="<?=$row->id_siswa;?>" data-col="n2"
name="data[<?php echo $row->id_siswa;?>]n2" style="width: 35px; text-align: center; padding: 0px;"></td>
                <td><input type="text"
data-siswaid="<?=$row->id_siswa;?>" data-col="n3"
name="data[<?php echo $row->id_siswa;?>]n3" style="width: 35px; text-align: center; padding: 0px;"></td>
                <td><input type="text"
data-siswaid="<?=$row->id_siswa;?>" data-col="n4"
name="data[<?php echo $row->id_siswa;?>]n4" style="width: 35px; text-align: center; padding: 0px;"></td>
                <td><input type="text"
data-siswaid="<?=$row->id_siswa;?>" data-col="n5"
name="data[<?php echo $row->id_siswa;?>]n5" style="width: 35px; text-align: center; padding: 0px;"></td>
                <td><input type="text"
data-siswaid="<?=$row->id_siswa;?>" data-col="n6"
name="data[<?php echo $row->id_siswa;?>]n6" style="width: 35px; text-align: center; padding: 0px;"></td>
                <td><input type="text" name="na" readonly style="width: 35px; text-align: center; padding: 0px;" value=""></td>
                <td><input type="text" name="data[<?php echo $row->id_siswa;?>]des" style="width: 100%; padding: 0px;"></td>
                <td><button type="button" id="btn-save" class="btn btn-xs btn-info"><i class="fa fa-save"></i> Simpan</button></td>
              </tr>
              <?php } ?>
              </tbody>
            </form>
</table>