pertama perbaiki dulu kode loginnya:
<?
session_start();
$email=$_POST['email'];
$pass=$_POST['pass'];
$domain=$_POST['domain'];
$userDom=$email.''.$domain;
 
$Conn=new Connection(DB_USER,DB_PASS,DB);
$Conn->Query("SELECT * FROM pegawai WHERE email= :usr");
$Conn->createConnection();
$Conn->bindFetch(':usr',$userDom);
 
if($Conn->getRow('NOMOR')!=''){
	if($Conn->getRow('PASSWORD')==$pass){
		//cek apakah staff kepegawaian
		$no=$Conn->getRow('NOMOR');
		if($Conn->getRow('STAFF')=='19'){
			// session dulu baru header
			$_SESSION['userKepeg']=$no;
			$_SESSION['nama']=$Conn->getRow('NAMA');
			header('Location: index.php?page=kepeg');
		}
		else{
			$Conn->Query("SELECT * FROM pegawai_tugas_tambahan WHERE pegawai='".$Conn->getRow('NOMOR')."'");
			$Conn->fetch();
			$jab = $Conn->getRow('JABATAN');
			$arrJab = array('2','3','7','111');
			if(in_array($jab,$arrJab)){
				$_SESSION['userJur']=$no;
				header('Location: index.php?page=jurusan');
			}
		}
	}
	else{
		header('Location: index.php?salah=pass');
	}
}
else{
	header('Location: index.php?salah=user');
}
?>
dihalaman login ditambahkan seperti ini:
<?php
session_start();
if(isset($_SESSION['userKepeg']) && $_SESSION['userKepeg']){
	header('Location: index.php?page=kepeg');
	exit;
}
if(isset($_SESSION['userJur']) && $_SESSION['userJur']){
	header('Location: index.php?page=jurusan');
	exit;
}