iframe切入切出

driver.switch_to_frame('LAY_layedit_1')

driver.find_element_by_xpath('/html/body').send_keys(u'连云港采购处')

driver.switch_to_default_content()
driver.find_element_by_xpath('/html/body/div[1]/div[4]/div/div/div[2]/form/div[9]/button[2]').click()