【Selenium】【BugList8】126邮箱定位不到“退出”按钮：Message: TypeError: can't access dead object

#coding=utf-8
from selenium import webdriver

driver = webdriver.Firefox()
#driver = webdriver.Ie()
driver.implicitly_wait(10)
driver.get("https://mail.126.com/")

#切换到frame
driver.switch_to.frame("x-URS-iframe")
#输入密码、用户名,登录

driver.find_element_by_name("password").clear()
driver.find_element_by_name("password").send_keys("xxx")
driver.find_element_by_name("email").clear()
driver.find_element_by_name("email").send_keys("yyy")

driver.find_element_by_id("dologin").click()

#退出
driver.find_element_by_xpath("/html/body/header/div[1]/ul[1]/li[16]/a").click()
driver.quit()
#coding=ut