Tamam burada durum, ben örneğin bir giriş formu kullanmak istiyorum

<form name="form1" method="post" action="sign.php">
    Username:<br/>
    <input name="myusername" type="text" id="myusername" /><br />
    Password:<br />
    <input name="mypassword" type="text" id="mypassword" /><br />
    <input type="submit" name="Submit" value="Login" />
</form>

sign.php

<?php
ob_start();
$host="localhost"; // Host name 
$username="root"; // Mysql username 
$password=""; // Mysql password 
$db_name="cosmos"; // Database name 
$tbl_name="members"; // Table name

// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");

// Define $myusername and $mypassword 
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];

// To protect MySQL injection (more detail about MySQL injection)
$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);
$mypassword = md5($mypassword);

$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row

if($count==1){
// Register $myusername, $mypassword and redirect to file "login_success.php"
session_register("myusername");
session_register("mypassword"); 
header("location:login_success.php");
}
else {
echo "Wrong Username or Password";
}

    ob_end_flush();
?>

Kullanıcı yanlış bilgi girerse durumda sonra ben bu biraz şey gibi ... "Yanlış Kullanıcı Adı veya Şifre Lütfen tekrar deneyin ..." formun aynı sayfada görünmesini istediğiniz ve biz alt formu var