/*
   name - name of the cookie
   value - value of the cookie
   [expires] - expiration date of the cookie
     (defaults to end of current session)
   [path] - path for which the cookie is valid
     (defaults to path of calling document)
   [domain] - domain for which the cookie is valid
     (defaults to domain of calling document)
   [secure] - Boolean value indicating if the cookie transmission requires
     a secure transmission
   * an argument defaults when it is assigned null as a placeholder
   * a null placeholder is not required for trailing omitted arguments
*/

function setCookie(name, value, days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+days*86400);
        var expires = "; expires="+date.toGMTString();
    }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}