มีโค้ดด้านในครับ ให้พอล็อกผิด 3 ครั้ง ก็จะเด้งไปอีกหน้าหนึ่ง

$sql= "select *from admin where admin='$admin' and password='$password_md5'";
$result = mssql_query($sql);
$num_rows=mssql_num_rows($result);
			
			if($num_rows==1) 
			{
			header("location:check_admin2.php");
			isset($_SESSION['check_admin']=0;
			}
				else{

				echo "<script>alert('username and password incorrect');window.location = 'admin.php';</script>";
				$_SESSION['check_admin']++;
				if($_SESSION['check_admin']==3)
				{header('location:home.php');
				}
			}

<?

session_start();
session_register("check_admin");

include("config.inc.php");

$admin=$_POST["admin"];
$password_md5 = md5($_POST["password"]);

$sql= "select *from admin where admin='$admin' and password='$password_md5'";
$result = mysql_query($sql);
$num_rows=mysql_num_rows($result);

if($num_rows != 0) {
	header("location:check_admin2.php");
	$_SESSION["check_admin"] = 0;
}

else{
	echo "<script>alert('username and password incorrect');window.location = 'admin.php';</script>";
	$_SESSION["check_admin"]++;

	if($_SESSION("check_admin"] >= 3){
		header('location:home.php');
	}
}

?>

<?
session_start();
if(isset($_SESSION['count'])){ $_SESSION['count'] = 0; }
include('config.inc.php');
$admin=$_POST['admin'];
$_SESSION['admin']=$admin;
$password=$_POST['password'];
$password_md5 = md5($password);

if(empty($admin))
	{
		echo "<script>alert('Please input your username');window.location = 'admin.php';</script>";
		exit();
	}
else if(empty($password))
	{
		echo "<script>alert('Please input your password');window.location = 'admin.php';</script>";
		exit();
	}
else{
	$sql= "select *from admin where admin='$admin' and password='$password_md5'";
	$result = mssql_query($sql);
	$num_rows=mssql_num_rows($result);	
				if($num_rows==1){ header("location:check_admin2.php"); }
				else{
					echo "<script>alert('username and password incorrect');window.location = 'admin.php';</script>";
					$_SESSION['count']++;
					if($_SESSION['count']>=3)
					{
					   $_SESSION['count']=0;
					   header("location:home.php");}
					}
}
?>

if($num_rows==1){
header("location:check_admin2.php");
$_SESSION['check_admin']=0;
}

if($num_rows==1){
if(isset($_SESSION['check_admin'])){
$_SESSION['check_admin'] = $_SESSION['check_admin'] +1;
}else{
$_SESSION['check_admin']=0;
}
header("location:check_admin2.php");
}
if($_SESSION['check_admin']==3){
header('location:home.php');
}

<?
session_start();
session_register("check_admin");

include("config.inc.php");

//$host = "localhost";
//$user = "root";
//$pwd = "1234";
//$dbname = "dbname";

//mysql_connect($host,$user,$pwd) or die("ไม่สามารถติดต่อฐ้านข้อมูลได้");
//mysql_select_db($dbname) or die("ไม่สามารถเลือกฐานข้อมูลได้");

$admin=$_POST["admin"];
$password_md5 = md5($_POST["password"]);
$sql= "select * from admin where admin='$admin' and password='$password_md5'";
$result = mysql_query($sql);
$num_rows=mysql_num_rows($result);

if($num_rows == 0) {
	if($_SESSION["check_admin"] >= 3){
		echo "<script>alert('กรอกชื่อผู้ใช้หรือรหัสผ่านผิดเกินกว่าที่กำหนด');window.location = 'home.php';</script>";
		$_SESSION["check_admin"] = 0; // กลับมาใหม่จะได้เป็น 0
	}
	else{
		echo "<script>alert('กรอกชื่อผู้ใช้หรือรหัสผ่านผิด');window.location = 'admin.php';</script>";
		$_SESSION["check_admin"]++;
	}
}
else{
	$_SESSION["check_admin"] = 0;
	header("location:check_admin2.php");
}
?>