def image(value, width='', height=''):
    """
    Accepts a URL and returns an HTML image tag ready to be displayed.

    Optionally, you can set the height and width with keyword arguments.
    """
    style = ""
    if width:
        style += "width:%s" % width
    if height:
        style += "height:%s" % height
    data_dict = dict(src=value, style=style)
    return '<img src="%(src)s" style="%(style)s">' % data_dict