Make AJAX request to `url` with given POST `data`. Call `on_complete`
    callback when complete.

    Args:
        url (str): URL.
        data (dict): Dictionary with POST data.
        on_complete (ref): Reference to function / method which will be called
            when the request is done.

def make_request(url, data, on_complete):
    """
    Make AJAX request to `url` with given POST `data`. Call `on_complete`
    callback when complete.

    Args:
        url (str): URL.
        data (dict): Dictionary with POST data.
        on_complete (ref): Reference to function / method which will be called
            when the request is done.
    """
    req = ajax.ajax()
    req.bind('complete', on_complete)
    req.open('POST', url, True)
    req.set_header('content-type', 'application/x-www-form-urlencoded')
    req.send(data)