proseslogin

<?php
include 'koneksi.php';
$username = $_POST['username'];
$password = $_POST['password'];

$sql = mysqli_query($connect, "select * from user where username= '$username' and password= '$password'");
$check = mysqli_num_rows($sql);

if($check>0)
{
    header("location:index.html");
}else{
    header("location:login.php");
}