$clave=$_POST['clave'];
$pass = password_hash($clave, PASSWORD_DEFAULT);

$clave='123'.$username.'IME';
$pass = password_hash($clave, PASSWORD_DEFAULT);

$claveold=$_POST['claveold'];
$clavenew=$_POST['clavenva'];
$oldpass = password_hash($claveold, PASSWORD_DEFAULT);
$pass = password_hash($clavenew, PASSWORD_DEFAULT);

$clave = $_POST['clave'];
//$pass = password_hash($clave, PASSWORD_BCRYPT);
$pass = password_hash($clave, PASSWORD_DEFAULT);
$grupo = $_POST['grupo'];
$error = '';
$sql011 = "SELECT 98_idusr, 98_username, 98_clave, 98_grupo FROM $t98 WHERE 98_username = '$username' AND 98_clave = '$pass' AND 98_grupo = '$grupo'";
$res011 = mysqli_query($conexion,$sql011);
$rows=$res011->num_rows;
if ($rows > 0) {
    $row = $res011->fetch_assoc();