nambah menu bayar buat bulan apa? di sisilah KTSP 2006

mohon bantuanya mas robi saya akan menambahakan menu tambahan bayaran bulan ke ke berapa.  di bagian pembayaran 
 
 
tampilanya seperti ini, cuman terkendalan di bagian script phpnya.
 
 
<?php 
if ($_GET[act]==''){ 
?> 
            <div class="col-xs-12">  
              <div class="box">
                <div class="box-header">
                  <h3 class="box-title">Pembayaran Keuangan Siswa </h3>
                  <form [removed]='padding:4px'>
                        <?php 
                            echo "<option value=''>- Pilih Jenis Biaya -</option>";
                            $biaya = mysql_query("SELECT * FROM rb_keuangan_jenis");
                            while ($k = mysql_fetch_array($biaya)){
                              if ($_GET[biaya]==$k[id_keuangan_jenis]){
                                echo "<option value='$k[id_keuangan_jenis]' selected>$k[nama_jenis]</option>";
                              }else{
                                echo "<option value='$k[id_keuangan_jenis]'>$k[nama_jenis]</option>";
                              }
                            }
                        ?>
                    </select>
                    <select name='kelas' [removed]='margin-top:-4px' class='btn btn-info btn-sm' value='Lihat'>
                  </form>
                </div><!-- /.box-header -->
                <div class="box-body">
 
                <?php 
                  if (isset($_GET['sukses'])){
                      echo "<div class='alert alert-success alert-dismissible fade in' role='alert'> 
                          <button type='button' class='close' data-dismiss='alert' aria-label='Close'>
                          <span aria-hidden='true'>×</span></button> <strong>Sukses!</strong> - Data telah Berhasil Di Proses,..
                          </div>";
                  }elseif(isset($_GET['gagal'])){
                      echo "<div class='alert alert-danger alert-dismissible fade in' role='alert'> 
                          <button type='button' class='close' data-dismiss='alert' aria-label='Close'>
                          <span aria-hidden='true'>×</span></button> <strong>Gagal!</strong> - Data tidak Di Proses, terjadi kesalahan dengan data..
                          </div>";
                  }
                ?>
 
                <form action='' method='POST'>
                <input type="hidden" name='kelas' value='<?php echo $_GET[kelas]; ?>'>
                <?php 
                $j = mysql_fetch_array(mysql_query("SELECT * FROM `rb_keuangan_jenis` where id_keuangan_jenis='$_GET[biaya]'"));
                $th = mysql_fetch_array(mysql_query("SELECT * FROM rb_tahun_akademik where aktif='Ya'"));
                echo "<table id='example1' class='table table-bordered table-striped'>
                    <thead>
                    <tr><th width='30px'>No</th>
                        <th>NIPD</th>
                        <th>NISN</th>
                        <th>Nama Siswa</th>
                        <th>Kelas</th>";
                        if ($_GET[kelas] != '' AND $_GET[biaya] != ''){
                          if ($j[total_beban] != '0'){
                            echo "<th>Status</th>";
                          }
                        }
 
                        echo "<th width='140px'>Action</th>
                        </tr>
                    </thead>
                    <tbody>";
 
                  if ($_GET[kelas] != '' AND $_GET[biaya] != ''){
                    $tampil = mysql_query("SELECT * FROM rb_siswa a LEFT JOIN rb_kelas b ON a.kode_kelas=b.kode_kelas 
                                              LEFT JOIN rb_jenis_kelamin c ON a.id_jenis_kelamin=c.id_jenis_kelamin 
                                                LEFT JOIN rb_jurusan d ON b.kode_jurusan=d.kode_jurusan 
                                                  where a.kode_kelas='$_GET[kelas]' ORDER BY a.id_siswa");
                  }
                    $no = 1;
                    while($r=mysql_fetch_array($tampil)){
                    $t = mysql_fetch_array(mysql_query("SELECT sum(total_bayar) as total FROM `rb_keuangan_bayar` where id_keuangan_jenis='$_GET[biaya]' AND kode_kelas='$r[kode_kelas]' AND nisn='$r[nisn]' AND tahun_akademik='$th[id_tahun_akademik]'"));
                    if ($j[total_beban] <= $t[total]) { $status = 'Lunas'; $class = 'green'; }else{ $status = 'Belum Lunas'; $class = 'red'; }
                    echo "<tr><td>$no</td>
                              <td>$r[nipd]</td>
                              <td>$r[nisn]</td>
                              <td>$r[nama]</td>
                              <td>$r[nama_kelas]</td>";
                              if ($_GET[kelas] != '' AND $_GET[biaya] != ''){
                                if ($j[total_beban] != '0'){
                                  echo "<td><i [removed]='padding:60px; color:red'>Silahkan Memilih Jenis Biaya dan Kelas Terlebih dahulu...</center>";
                    }
                ?>
              </div><!-- /.box -->
              </form>
            </div>
<?php 
}elseif($_GET[act]=='detail'){
    if (isset($_POST[proses])){
        $th = mysql_fetch_array(mysql_query("SELECT * FROM rb_tahun_akademik where aktif='Ya'"));
        $query = mysql_query("INSERT INTO rb_keuangan_bayar VALUES('','$_POST[a]','$_POST[b]','$_POST[c]','$th[id_tahun_akademik]','$_POST[bayar]','".date('Y-m-d H:i:s')."')");
        if ($query){
          echo "[removed][removed]='index.php?view=pembayaransiswa&act=detail&biaya=$_POST[a]&nisn=$_POST[c]&sukses';[removed]";
        }else{
          echo "[removed][removed]='index.php?view=pembayaransiswa&act=detail&biaya=$_POST[a]&nisn=$_POST[c]&gagal';[removed]";
        }
    }
 
    $d = mysql_fetch_array(mysql_query("SELECT * FROM `rb_siswa` a JOIN rb_kelas b ON a.kode_kelas=b.kode_kelas where a.nisn='$_GET[nisn]'"));
    $j = mysql_fetch_array(mysql_query("SELECT * FROM `rb_keuangan_jenis` where id_keuangan_jenis='$_GET[biaya]'"));
    $t = mysql_fetch_array(mysql_query("SELECT sum(total_bayar) as total FROM `rb_keuangan_bayar` where id_keuangan_jenis='$_GET[biaya]' AND kode_kelas='$d[kode_kelas]' AND nisn='$_GET[nisn]'"));
    $sisa = $t[total]-$j[total_beban];
    if ($j[total_beban] <= $t[total]) { $status = 'Lunas'; $class = 'success'; }else{ $status = 'Belum Lunas'; $class = 'danger'; }
            echo "<div class='col-xs-12'>  
              <div class='box'>
                <div class='box-header'>
                  <h3 class='box-title'>Data Pembayaran Keuangan Siswa</h3>
                  <a class='pull-right btn btn-sm btn-warning' href='index.php?view=pembayaransiswa&biaya=$_GET[biaya]&kelas=$d[kode_kelas]'>Kembali</a>
                </div>
                <div class='box-body'>";
 
                  if (isset($_GET['sukses'])){
                      echo "<div class='alert alert-success alert-dismissible fade in' role='alert'> 
                          <button type='button' class='close' data-dismiss='alert' aria-label='Close'>
                          <span aria-hidden='true'>×</span></button> <strong>Sukses!</strong> - Data telah Berhasil Di Proses,..
                          </div>";
                  }elseif(isset($_GET['gagal'])){
                      echo "<div class='alert alert-danger alert-dismissible fade in' role='alert'> 
                          <button type='button' class='close' data-dismiss='alert' aria-label='Close'>
                          <span aria-hidden='true'>×</span></button> <strong>Gagal!</strong> - Data tidak Di Proses, terjadi kesalahan dengan data..
                          </div>";
                  }
 
                echo "<div class='col-md-12'>
                  <form action='' method='POST'>
                  <table class='table table-condensed table-hover'>
                      <tbody>
                        <tr><th width='120px' scope='row'>Nama Kelas</th> <td>$d[nama_kelas]</td></tr>
                        <tr><th scope='row'>Nama Siswa</th>           <td>$d[nama]</td></tr>
                        <tr><th scope='row'>Jenis Biaya</th>           <td>$j[nama_jenis]</td></tr>";
 
                        if ($sisa < 0){
                          echo "<input type='hidden' value='$j[id_keuangan_jenis]' name='a'>
                                <input type='hidden' value='$d[kode_kelas]' name='b'>
                                <input type='hidden' value='$_GET[nisn]' name='c'>
                                <tr><th scope='row'>Bayar Sisa</th>           
        <td><input type='text' name='bayar' value=''> Bayar Bulan : <input type='date' name='date' value=''>  <input type='submit' name='proses' value=' Proses'></td></tr>";
                        }
 
                        if ($j[total_beban] > '0'){
                        echo "<tr><th scope='row'>Total Beban</th>           <td>Rp ".number_format($j[total_beban])."</td></tr>
                                <tr><th scope='row'>Total Bayar</th>           <td>Rp ".number_format($t[total])."</td></tr>
                                <tr class='alert alert-$class'><th scope='row'>Sisa</th>           <td>Rp ".number_format($t[total]-$j[total_beban])." <small class='pull-right'>$status</small></td></tr>";
                        }
 
                        if ($j[total_beban] == '0'){
                          echo "<tr><th scope='row'>Total </th>           <td>Rp ".number_format($t[total])."</td></tr>
                              <input type='hidden' value='$j[id_keuangan_jenis]' name='a'>
                              <input type='hidden' value='$d[kode_kelas]' name='b'>
                              <input type='hidden' value='$_GET[nisn]' name='c'>
                              <tr><th scope='row'>Bayar</th>           <td><input type='text' name='bayar' value=''> <input type='submit' name='proses' value='Proses'></td></tr>";
                        }
 
                      echo "</tbody>
                  </table>
                  </form>
                  </div>
 
 
                  <table id='example' class='table table-bordered table-striped'>
                    <thead>
                      <tr>
                        <th [removed]='width:80px !important'><center>
                                        <a class='btn btn-danger btn-xs' title='Delete Data' href='index.php?view=pembayaransiswa&act=detail&biaya=$_GET[biaya]&nisn=$_GET[nisn]&hapus=$r[id_keuangan_bayar]'><span class='glyphicon glyphicon-remove'></span></a>
                                      </center></td>";
                              }
                            echo "</tr>";
                      $no++;
                      }
 
                      if (isset($_GET[hapus])){
                        mysql_query("DELETE FROM rb_keuangan_bayar where id_keuangan_bayar='$_GET[hapus]'");
                        echo "[removed][removed]='index.php?view=pembayaransiswa&act=detail&biaya=$_GET[biaya]&nisn=$_GET[nisn]';[removed]";
                      }
 
                    echo "<tbody>
                  </table>
                </div>
                </div>
            </div>";
}
?>