function round_corners() {
    settings = {
        tl: { radius: 10 },
        tr: { radius: 10 },
        bl: { radius: 10 },
        br: { radius: 10 },
        antiAlias: true,
        autoPad: false
    }
    var divObj = document.getElementById("mainDiv");
    var cornersObj = new curvyCorners(settings, divObj);
    cornersObj.applyCornersToAll();
}

addEvent(window, "load", round_corners);