Mohon pencerahan untuk input data ke database noreg_simper.php

Asallam, 
Halo suhu mohon bantuan ya,  
 
Berikut syntax yang perlu dibenahi : 
 
1. Untuk HALAMAN View 
//tambah-karyawan.php
 <?php include('system/conf/koneksi.php');?>
 
<!-- CEGAH BY PASS PERHALAMAN -->
<?php
    if (isset($_POST[tambah])){
            $noreg_simper = $_POST[ra]."/".$_POST[rb]."/".$_POST[rc]."/".$_POST[rd];
 
            mysql_query("INSERT INTO data_karyawan VALUES('$nomor','$noreg_simper','$_POST[nik]','$_POST[nama]','$_POST[tgl_pengajuan]',                                '$_POST[masa_mcu]','$_POST[jabatan]','$_POST[departemen]','$masa_simper')");
        $id = mysql_insert_id();                             
                        echo "<script>document.location='index.php?view=kegiatan&act=edit&id=".$id."';</script>";
    }
?>
 
<?php 
if(!isset($_SESSION['admin'])){
    echo '<script language="javascript">alert
    ("Anda harus login dulu!");document.location="login.php?page=masuk";</script>';	
}
?>
<?php
$data = mysql_query("select * from noreg_simper order by nomor DESC LIMIT 0,1");
$i= mysql_fetch_array($data) ;
// ID OTOMATIS//***************************************************
$kodeawal=substr($i['nomor'],3,4);
if($kodeawal<10){
  $kode='005'.$kodeawal;
}elseif($kodeawal > 9 && $kodeawal <=99){
  $kode='1100'.$kodeawal;
}else{
  $kode='11000'.$kodeawal;
}
 ?>
 
 
 
 
 
<div class="row">
                <div class="col-lg-12">
                    <h2 class="page-header">Tambah Karyawan</h2>
                </div>
                <!-- /.col-lg-12 -->
            </div>
            <!-- /.row -->
            <div class="row">
                <div class="col-lg-12">
                    <div class="panel-default">
                        <div class="panel-heading">
Formulir penambahan Data Karyawan
</div>
                        <div class="panel-body">
                            <div class="row">
                                <div class="col-lg-6">
               <form action="tambah-karyawan-proses.php" method="post">
 
<div class="form-group"><b><i>No. Reg Simper :</i></b> 
 
  <input type="text" name="ra" value="<?php echo $kode ;?>" size="8" maxlength="4"/> 
  <strong>/</strong>
  <input type="text" name="rb" readonly value="BUMA-BMO" size="8" maxlength="8"/>
  <strong>/</strong>
  <input type="text" name="rc" size="4" value="<?php
    $array_bulan = array(1=>"I","II","III", "IV", "V","VI","VII","VIII","IX","X", "XI","XII");
    $bulan = $array_bulan[date('n')];
 
    echo  "$bulan";
?>"maxlength="4"/> 
  <strong>/</strong>
  <input type="text" name="rd" value="<?php
    $tahun_sekarang = date('Y');
    $tahun = substr($tahun_sekarang, -2);
 
    echo "$tahun";
?>"size="4" maxlength="2"/>
</div>
 
 
<div class="form-group"><b>NIK :</b> 
 
  <input class="form-control" placeholder="NIK Karyawan" id="nik" name="nik" required="">
</div>
 
<div class="form-group">
Nama Karyawan : 
<input class="form-control" placeholder="Nama Karyawan" id="nama" name="nama" required="">
</div>
<p>Tanggal Pengajuan: 
    <input type ="date" class="form-control" placeholder="tgl_pengajuan" id="tgl_pengajuan" name="tgl_pengajuan" required="required" />
</p>
<div>
  <p>Masa MCU : 
    <input type ="date" class="form-control" placeholder="masa_mcu" id="masa_mcu" name="masa_mcu" required="required" />
</p>
</div>
<div class="form-group"></div>
<div class="form-group">
 
<script src="jquery-3.3.1.js"></script> <script type="text/javascript"> $(document).ready(function(){ $('#idcardlama').hide(); $('#show').on('change', function () { var optionSelected = $("option:selected", this); var valueSelected = this.value; if(valueSelected == 2){ $("#idcardlama").show(); }else{ $("#idcardlama").hide(); } }); }); 
</script></div> <div class="form-group"> 
 
<link href="metro.css" rel="stylesheet">  
<script src="jquery-2.1.3.min.js"></script>  
<script src="metro.js"></script>
 
<form action="status_kerja"> 
<p>Jabatan :
 <select class="form-control" name="jabatan" type="text" id="jabatan">
<option value="">-SILAHKAN PILIH-</option>
<?php
 
//mengambil nama-nama departemen yang ada di database
$function= mysql_query("SELECT * FROM departemen ORDER BY position");
while($p=mysql_fetch_array($function)){
echo "<option value=\"$p[id]\">$p[position]</option>\n";
}
?>
 
</select>
</p>
<p>Departemen :
  <select class="form-control" name="departemen" type="text" id="departemen">
<option value="">-SILAHKAN PILIH-</option>
<?php
 
//mengambil nama-nama departemen yang ada di database
$function= mysql_query("SELECT * FROM function ORDER BY function");
while($p=mysql_fetch_array($function)){
echo "<option value=\"$p[id]\">$p[function]</option>\n";
}
?>
 
</select>
</p>
<div>
<p><b>Masa Simper :</b> 
  <input type ="date" class="form-control" placeholder="masa_simper" id="masa_simper" name="masa_simper" required="required" />
</p>
</div>
  </div> 
<button type="submit" class="btn btn-primary" name="tambah" id="tambah">Tambah</button> <button type="reset" class="btn btn-default">Batal</button>  <button type="reset" class="btn btn-default">Reset</button>
</form>              
 
2. Untuk Halaman Proses 
 
tambah-karyawan-proses.php 
 
<?php
include'system/conf/koneksi.php';
$noreg_simper=$_POST['noreg_simper'];
$nik=$_POST['nik'];
$nama=$_POST['nama'];
$tgl_pengajuan=$_POST['tgl_pengajuan'];
$masa_mcu=$_POST['masa_mcu'];
$jabatan=$_POST['jabatan'];
$departemen=$_POST['departemen'];
$masa_simper=$_POST['masa_simper'];
 
if(isset($_POST['simpan'])){
	mysql_query(
		"INSERT INTO noreg_simper
		VALUES('$noreg_simper','$nik','$nama','$tgl_pengajuan','$masa_mcu','$jabatan','$departemen','$masa_simper)"
	);
	header("location:pages/index.php");
}
?>