我不能用散列的密码登录

我有以下代码注册，它散列密码，我可以看到在数据库中成功散列

function newUser() {
    $forename = $_POST['forename'];
    $surname = $_POST['surname'];
    $email = $_POST['email'];
    $securityq = $_POST['securityq'];
    $securitya = $_POST['securitya'];
    $password =  $_POST['password'];
    $hash = password_hash ($password, PASSWORD_BCRYPT );
    $query = "INSERT INTO admin (forename,surname,email,securityq, securitya,password) VALUES ('$forename','$surname','$email','$securityq','$securitya','$hash')";

    $data = mysql_query ($query)or die(mysql_error());
    if($data)
        {
    }
}

和下面的代码是我的登录页面:

$email = $_POST['email'];
$password = $_POST['pass'];

function SignIn()
{
    session_start();
    if (!empty($_POST['email']))
    {
        $query = mysql_query ("SELECT * FROM admin where email = '$_POST[email]' AND password = '$_POST[pass]'");
        $row = mysql_fetch_array ($query);
        if(!empty($row['email']) AND !empty($row['password']))
        {
            $_SESSION['email'] = $row['password'];
            echo ("<SCRIPT LANGUAGE='JavaScript'>
            window.alert('Successful Login')
            window.location.href='adminhome.php';
            </SCRIPT>");
        }
        else
        {
            echo ("<SCRIPT LANGUAGE='JavaScript'>
            window.alert('Invalid Login Credentials')
            window.location.href='adminsignin.php';
            </SCRIPT>");
        } 
    }
}
if(isset($_POST['submit']))
{
    SignIn();
}

但是我用密码根本无法登录。我已经摆弄了代码的签名，但找不到我需要改变来解决这个问题，非常感谢，提前。