tricky input

<?php
foreach($data_pelajaran->result_array() as $row){
?>
<tr class="gradeA odd">
<td>
   <input type="checkbox" value="<?php echo $row['id_pengajar'];?>" name="id_pengajar[]">
</td>
<td><?php echo $row['nama_guru']; ?></td>
<td><?php echo $row['nama_pelajaran']; ?></td>
<td><input type="text" class="maskTime" id="maskTime" name="dari_jam<?php echo $row['id_pengajar'];?>"  ></td>
<td><input type="text" class="maskTime" id="maskTime" name="sampai_jam<?php echo $row['id_pengajar'];?>" ></td>
</tr>
<?php
}
?>

===
public function add_detail(){
  $id_jadwal = $this->input->post('id_jadwal',true);
  $id_pengajar = $this->input->post('id_pengajar',true);
  for($i=0;$i<count($id_pengajar);$i++)
  {
    $data['id_jadwal'] = $id_jadwal;
    $data['id_pengajar'] = $id_pengajar[$i];
    $data['dari_jam'] = $this->input->post('dari_jam'.$id_pengajar[$i],true);
    $data['sampai_jam'] = $this->input->post('sampai_jam'.$id_pengajar[$i],true);
    $this->model_jadwal->add_detail($data);
  }
}