takes a given wildcard string and deletes any cookies that contain it in the name

deleteCookiesByPattern

function deleteCookiesByPattern(pattern){
    var cookies = document.cookie.split(';');
    for(var i=0;i<=cookies.length;i++){
        var ck = cookies[i];
        if(/pattern/.test(ck)){
            document.cookie = ck + '=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT;'
        }
    }
}