Подскажите с доработкой интересного скрипта

function PopShow3() {
CookieTest=navigator.cookieEnabled;
if (CookieTest) {
ClickUndercookie = GetCookie('clickunder');
if (ClickUndercookie == null) {
var ExpDate = new Date ();
ExpDate.setTime(ExpDate.getTime() + (24 * 60 * 60 * 1000));
SetCookie('clickunder','1',ExpDate, "/");
window.open("http://нужныйсайт.ru","PopWin3","resizable=1,toolbar=1,location=1,menubar=1,status=1,scrollbars=1");
window.focus();
}
}
}

function GetCookie (name) {
var arg = name + "=";
var alen = arg.length;
var clen = document.cookie.length;
var i = 0;
while (i < clen) {
var j = i + alen;
if (document.cookie.substring(i, j) == arg)
return getCookieVal (j);
i = document.cookie.indexOf(" ", i) + 1;
if (i == 0) break;
}
return null;
}

function SetCookie (name, value) {
var argv = SetCookie.arguments;
var argc = SetCookie.arguments.length;
var expires = (argc > 2) ? argv[2] : null;
var path = (argc > 3) ? argv[3] : null;
var domain = (argc > 4) ? argv[4] : null;
var secure = (argc > 5) ? argv[5] : false;
document.cookie = name + "=" + escape (value) +
((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
((path == null) ? "" : ("; path=" + path)) +
((domain == null) ? "" : ("; domain=" + domain)) +
((secure == true) ? "; secure" : "");
}

document.onmouseup=PopShow3;