how to delete a cookie in js

1function deleteAllCookies() {
2    var cookies = document.cookie.split(";");
3
4    for (var i = 0; i < cookies.length; i++) {
5        var cookie = cookies[i];
6        var eqPos = cookie.indexOf("=");
7        var name = eqPos > -1 ? cookie.substr(0, eqPos) : cookie;
8        document.cookie = name + "=;expires=Thu, 01 Jan 1970 00:00:00 GMT";
9    }
10}
11
12deleteAllCookies();

1function deleteCookie(name) {
2  document.cookie = name + '=; expires=Thu, 01 Jan 1970 00:00:01 GMT;';
3}

1//set the vvalue to EMPTY, and the date to an already PASSED one.
2document.cookie = "cookiename= ; expires = Thu, 01 Jan 1970 00:00:00 GMT"

1var removing = browser.cookies.remove(
2  details               // object
3)
4

1
2document.cookie = "username=; expires=Thu, 01 
3Jan 1970 00:00:00 UTC; path=/;";
4