javascript delete cookie

function deleteAllCookies() {
    var cookies = document.cookie.split(";");

    for (var i = 0; i < cookies.length; i++) {
        var cookie = cookies[i];
        var eqPos = cookie.indexOf("=");
        var name = eqPos > -1 ? cookie.substr(0, eqPos) : cookie;
        document.cookie = name + "=;expires=Thu, 01 Jan 1970 00:00:00 GMT";
    }
}

deleteAllCookies();function deleteCookie(name) {
  document.cookie = name + '=; expires=Thu, 01 Jan 1970 00:00:01 GMT;';
}//set the vvalue to EMPTY, and the date to an already PASSED one.
document.cookie = "cookiename= ; expires = Thu, 01 Jan 1970 00:00:00 GMT"var removing = browser.cookies.remove(
  details               // object
)