How to detect invalid Js cookie and remove it

I have set a cookie1 from [.abcsite.com]. when no domain mentioned from API it sets a cookie1 by default to [www.abcsite.com]. Now, the cookie1 gets duplicated, it creates issues in updating the value. How to delete cookie1 with [www.abcsite.com] domain only when cookie1 [.abcsite.com] domain is present as well.