def METHOD_NAME(self, callback_url, attrs="", http_post=False):
    """Create a OneID Sign In button on the web page"""
    challenge = {"attr" : attrs,
                 'auth_level' : "OOB",
                 "callback" : callback_url}
    if http_post:
        challenge["request_method"] = "HTTP_POST"
    params = json.dumps({"challenge" : challenge })
    js = "<span class='oneid_login_ctr'></span>"
    js+= "<script type='text/javascript'>"
    js+= "OneIdExtern.registerApiReadyFunction(function(){"
    js+= "OneId.loginButton('.oneid_login_ctr'," + params +")"
    js+= "})"
    js+="</script>"
    return js