<?php
$host="localhost"; // Host name
$username="root"; // Mysql username
$password=""; // Mysql password
$db_name="test2"; // Database name
$tbl_name="members"; // Table name
// Connect to server and select databse.
$link = mysqli_connect("$host", "$username", "$password")or die("cannot connect");
mysqli_select_db("$db_name")or die("cannot select DB");

// username and password sent from form
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];

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

// Mysql_num_row is counting table row
$count=mysqli_num_rows($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"
     header("location:login_success.php");
}
else {
echo "Wrong Username or Password";
}
?>