مشکل در هش کردن

کد HTML:

<?php    session_start();
    if(isset($_SESSION['xxx']))
    {
        include "pdocon.php";
        $id = $_POST['id'];
        $useame = $_POST['useame'];
        $password = $_POST['password'];
        $password = hash("sha256",$password);
        $querystring = "INSERT INTO admin (id,useame,password) VALUES (:id,:user,:pass)";
        $result = $coect->prepare($querystring);
        $result->execute(array(":id"=>$id,":user"=>$useame,":pass"=>$password));
        if($result)
        {
            header("location:admin.php?complite=82548");
            exit;
        }
        else
        {
            header("location:admin.php?error=5456");
            exit;
        }
    }
    else
    {
        header("location:login.php");
        exit;
    }
?>

کد HTML:

<?php    $useame_db = "root";
    $password_db = "";
    $serveame = "localhost";
    $dbname = "pdo";
    $dsn = "mysql:host=$serveame;dbname=$dbname";
    try
    {
        $coect = new PDO($dsn,$useame_db,$password_db);
        $coect->exec("SET CHARACTER SET utf8");
    }
    catch(PDOException $error)
    {
        echo "Error in conection".$error;
    }
?>