var rhstop = 0;

function findYPos(obj) {
    var curtop = 0;
    if (obj.offsetParent) {
        do {
            curtop += obj.offsetTop;
        } while (obj = obj.offsetParent);
    }
    return curtop;
}

function onScroll (e) {
    var adsenseUnit = document.getElementById("adsense-block-left");
    if ((document.documentElement.scrollTop + document.body.scrollTop) > 105) {
        adsenseUnit.style.position = "fixed";
        adsenseUnit.style.top = "0px";
    } else {
        adsenseUnit.style.position = "static";
    } 
    adsenseUnit = document.getElementById("adsense-block-right");
    if ((document.documentElement.scrollTop + document.body.scrollTop) > rhstop) {
        adsenseUnit.style.position = "fixed";
        adsenseUnit.style.top = "0px";
    } else {
        adsenseUnit.style.position = "static";
    } 
}

function bodyOnLoad() {
    var el = document.getElementById("adsense-block-right");
    rhstop = findYPos(el);
    window.onscroll = onScroll;
}