def is_cross_origin(request):
    """Compare headers HOST and ORIGIN. Remove protocol prefix from ORIGIN, then
    compare. Return true if they are not equal
    example HTTP_HOST: '127.0.0.1:5000'
    example HTTP_ORIGIN: 'http://127.0.0.1:5000'
    """
    origin = request.environ.get('HTTP_ORIGIN')
    host = request.environ.get('HTTP_HOST')
    if origin is None:
        return False
    if origin.startswith('http://'):
        origin = origin.replace('http://', '')
    elif origin.startswith('https://'):
        origin = origin.replace('https://', '')
    return host != origin
