<?php
    $host="localhost";
    $username="root";
    $password="alexi";
    $db_name="users";
    $tbl_name="accounts";

mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("db_name")or die("cannot select DB");

$username=$_POST['username'];
$password=$_POST['password'];

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

$count=mysql_num_rows($result);

if($count==1){

session_register("username");
session_register("password");
header("location.login_sucess.php");
}
else {
echo "Wrong!";
}
?>