import webbrowser

def open_website(url=""):
    """
    Opens a website in the default web browser.

    Args:
    - url: The URL of the website to open.

    Returns:
    - 'opened' if successful.
    - Error message if unsuccessful.
    """
    try:
        webbrowser.open(url)
        return "opened"
    except Exception as e:
        print("An error occurred:", e)
        return "An error occurred:", e