Cookie 1x per week for many weeks

HTML

<body>
    
</body>

JavaScript

function getCookie(cookieValue) {
    var i, x, y, ARRcookies = document.cookie.split(";");
    for (i=0; i<ARRcookies.length; i++) {
        x=ARRcookies[i].substr(0,ARRcookies[i].indexOf("="));
        y=ARRcookies[i].substr(ARRcookies[i].indexOf("=")+1);
        x=x.replace(/^\s+|\s+$/g,"");
        if (x === cookieValue) {
            return unescape(y);
        }    
    }
}

var myCounterCookieValue = getCookie("counterCookie");

if (document.cookie.indexOf("counterCookie") >= 0 && document.cookie.indexOf("my7DayCookie") >= 0){

    // BOTH COOKIES PRESENT, SO DO NOTHING

} else if (document.cookie.indexOf("counterCookie") >= 0 && myCounterCookieValue < 8 ){

    // SHOW MESSAGE BY INCLUDING MESSAGE CODE HERE

    // RESET THE my7DayCookie
    (function setMy7DayCookie(){
        var cookie = "my7DayCookie";
        var my7DayCookieValue = 1;
        var showAgain = new Date();
        showAgain.setDate(showAgain.getDate() + 7);
        var tmp=cookie + "=" + my7DayCookieValue + "; expires=" + showAgain.toGMTString() + "; path=/";
        document.cookie=tmp;
    })();

    // UPDATE counterCookie, INCREASE ITS VALUE BY 1
    (function setMyCounterCookie(){
        var cookie = "counterCookie";
        myCounterCookieValue++;
        var showAgain = new Date();
        showAgain.setDate(showAgain.getDate() + 99999);
        var tmp2=cookie + "=" + myCounterCookieValue + "; expires=" + showAgain.toGMTString() + "; path=/";
        document.cookie=tmp2;
        return myCounterCookieValue;
    })();

    //console.log("counterCookie Value = " + myCounterCookieValue);

} else if (myCounterCookieValue >= 8 ) {

    //DO NOTHING, THE USER HAS SEEN THE MESSAGE 8 TIMES

} else {

    // SHOW THE MESSAGE AND SET BOTH COOKIES FOR THE FIRST TIME

    (function setMyCookie(){
        var cookie = "my7DayCookie";
        var my7DayCookieValue = 1;
        var showAgain = new Date();
        showAgain.setDate(showAgain.getDate() + 7);
        var tmp=cookie + "=" +...