$email = $mysqli->escape_string($_POST['email']);
$result = $mysqli->query("SELECT * FROM accounts WHERE email='$email'");

if ( $result->num_rows == 0 ){ // User doesn't exist
$_SESSION['message'] = "User with that email doesn't exist!";
header("location: error.php");
}

else {  //User exists
$user = $result->fetch_assoc();

--> //$Act = $mysqli->query("SELECT $email FROM accounts WHERE active='1'");

--> if ( !$_SESSION['active'] = 1 )
  {

    $_SESSION['message'] = "Your account has been activated and is being reviewed";
    header("location: error.php");

   }

else
if ( password_verify($_POST['password'], $user['password']) ) {

    $_SESSION['email'] = $user['email'];
    $_SESSION['first_name'] = $user['first_name'];
    $_SESSION['last_name'] = $user['last_name'];
    $_SESSION['active'] = $user['active'];

    // This is how we'll know the user is logged in
    $_SESSION['logged_in'] = true;

    header("location: https://somepage.php");
}
else {
    $_SESSION['message'] = "You have entered wrong password, try again!";
    header("location: error.php");
}
}
 }

$email = $_POST['email'];

$stmt = $mysqli->prepare("SELECT * FROM accounts WHERE email = ?");
$stmt->bind_param("s", $email)
$stmt->execute();
$result = $stmt->get_result();
$num_of_rows = $result->num_rows;


if ( !$result || $num_of_rows == 0 ) {
    $_SESSION['message'] = "User with that email doesn't exist!";
    header("location: error.php");
    die();
}

$user = $result->fetch_assoc();
if ( $user['active'] != 1 ) {
    $_SESSION['message'] = "Your account has been activated and is being reviewed";
    header("location: error.php");
    die();
}

//password verification etc

if(empty($_SESSION) && !empty($_POST['email']))
    $email = $mysqli->escape_string($_POST['email']);
else
    $email = $_SESSION['email'];

$result = $mysqli->query("SELECT * FROM accounts WHERE email='$email'");

if ( !$result || $result->num_rows == 0 ){ // User doesn't exist
$_SESSION['message'] = "User with that email doesn't exist!";
header("location: error.php");
}

//User exists
$user = $result->fetch_assoc();
if($user['active'] != 1){//not active
    $_SESSION['email'] = $user['email'];
    $_SESSION['active'] = $user['active'];
    $_SESSION['message'] = "Your account has been activated and is being reviewed";
    header("location: error.php");
}

if ( password_verify($_POST['password'], $user['password']) ) {//valid password

    $_SESSION['email'] = $user['email'];
    $_SESSION['first_name'] = $user['first_name'];
    $_SESSION['last_name'] = $user['last_name'];
    $_SESSION['active'] = $user['active'];

    // This is how we'll know the user is logged in
    $_SESSION['logged_in'] = true;

    header("location: https://somepage.php");
}
$_SESSION['message'] = "You have entered wrong password, try again!";
header("location: error.php");

//receive data
$email = isset($_POST['email'])?$_POST['email']:null;
$password = isset($_POST['password'])?$_POST['password']:null;

//connect to database
$connection = new PDO("mysql:host=".$host.";dbname=".$dbName, $username, $password); //replace your credentials
$query = "SELECT * FROM accounts WHERE email = :email";
$statement = $connection->prepare($query);
$statement->bindParam(':email',$email); //bind $email variable to ':email'
$statemnet->execute(); //execute the query
if($statement->rowCount() > 0){
  $row = $statement->fetch();
  if($row['active'])){
    //user is active
    if(password_verify($password,$row['password'])){
      //password is correct
      $location = "success.php";
      //do some staff
    }else{
      //password is incorrect
      $location = "error.php";
    }
  }else{
    //user is not active
    $location = "error.php";
  }
}else{
  //user does no exists
  $location = "error.php";
}
header("Location: ".$location);