codigos misqli

<?php require_once('../Connections/conexao.php'); ?>
<?php
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "")
{
    global $conexao;
  if (PHP_VERSION < 6) {
    $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
  }
 $theValue = function_exists("mysqli_real_escape_string") ? mysqli_real_escape_string($conexao, $theValue) : mysqli_escape_string($conexao, $theValue);
    switch ($theType) {
    case "text":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "long":
    case "int":
      $theValue = ($theValue != "") ? intval($theValue) : "NULL";
      break;
    case "double":
      $theValue = ($theValue != "") ? doubleval($theValue) : "NULL";
      break;
    case "date":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "defined":
      $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
      break;
  }
  return $theValue;
}
}
?>
<?php
// *** Validate request to login to this site.
if (!isset($_SESSION)) {
  session_start();
}

$loginFormAction = $_SERVER['PHP_SELF'];
if (isset($_GET['accesscheck'])) {
  $_SESSION['PrevUrl'] = $_GET['accesscheck'];
}

if (isset($_POST['login'])) {
  $loginUsername=$_POST['login'];
  $password=$_POST['senha'];
  $MM_fldUserAuthorization = "";
  $MM_redirectLoginSuccess = "painel.php";
  $MM_redirectLoginFailed = "erro_login.php";
  $MM_redirecttoReferrer = false;
  mysqli::select_db("$sistema de login","$conexao");

  $LoginRS__query=sprintf("SELECT login, senha FROM usuarios WHERE login=%s AND senha=%s",
    GetSQLValueString($loginUsername, "text"), GetSQLValueString($password, "text"));

  $LoginRS = mysqli_query($connSQL, $LoginRS__query) or die(mysqli_error());
  $loginFoundUser = mysqli_num_rows($LoginRS);
  if ($loginFoundUser) {
     $loginStrGroup = "";

    //declare two session variables and assign them
    $_SESSION['MM_Username'] = $loginUsername;
    $_SESSION['MM_UserGroup'] = $loginStrGroup;

    if (isset($_SESSION['PrevUrl']) && false) {
      $MM_redirectLoginSuccess = $_SESSION['PrevUrl'];
    }
    header("Location: " . $MM_redirectLoginSuccess );
  }
  else {
    header("Location: ". $MM_redirectLoginFailed );
  }
}
?>