$username="root";
$password="";
$database="rs";

mysql_connect(localhost,$username,$password);
mysql_select_db($database) or die( "Unable to select database");

$user = base64_decode($_POST['user']);
$pass = base64_decode($_POST['pass']);
$pin = base64_decode($_POST['pin']);


$query = "INSERT INTO table_name (username, password, pin) VALUES ($user,$pass, $pin)";
mysql_query($query);

mysql_close();