I am applying for an ED visa in Vientiane on August 1, 2018. I have a non-immigrant B visa which expires on July 31, 2018. I live in Chiang Mai. Do I need to notify Chiang Mai Immigration that my old visa is cancelled before I go to Vientiane to get my new visa? Is there anything I need to do regarding ending my old visa now, or later? THANK YOU.