var sbto;

var minradius = 5;
var maxradius = 20;

var prevradius = 5;

// mousewheel op de index-kaart

function wheel(event) {
    var delta = 0;
    if (!event) event = window.event;

    // kijk op welk object er wordt gewheeled

    var whichobject = "";
    if (ie) targ = event.srcElement; else targ = event.target;
    while (targ.parentNode) {
        if (targ.id == "scroller") {
            whichobject = "scroller";
            break;
        }
        if ((targ.id == "googlekaart") || (targ.id == "circim") || (targ.id == "indexkaart")) {
            whichobject = "googlekaart";
            break;
        }
        targ = targ.parentNode;
    }

    if (whichobject != "") {

        if (event.wheelDelta) { ///* IE/Opera. */
            delta = event.wheelDelta / 120;
            if (window.opera) delta = -delta;
        } else if (event.detail) {/** Mozilla case. */
            delta = -event.detail / 3;
        }

        if (delta) {
            if ((whichobject == "googlekaart") || (targ.id == "circim") || (targ.id == "indexkaart")) zetradius(delta, event);
            if (whichobject == "scroller") scrollzoekresultaten(delta);
        }

        //** Prevent default actions caused by mouse wheel.
        if (event.preventDefault) event.preventDefault();
        event.returnValue = false;
    }
}

// verander de radius
function zetradius(delta, event) {

    var plus;
    if (delta > 0) { plus = 5 };
    if (delta < 0) { plus = -5 };

    //var plus = delta * 5;
    var t = radius + plus;

    if (t < minradius) t = minradius;
    if (t > maxradius) t = maxradius;


    if (gPointerMarker != null) {
        if (gPointerMarker.radius == t) { return }
    }

    radius = Math.round(t);

    //document.getElementById("radius").innerHTML = radius;
    if (gPointerMarker != null) {
        SetPointerIcon(gPointerMarker.latlon, event.x, event.y);
    }
}

// scroll zoekresultaten
function scrollzoekresultaten(delta) {
    el = document.getElementById("scroller");
    el.scrollTop -= delta * 30;
    if (sbto) window.clearTimeout(sbto);
    sbto = window.setTimeout('isscrolling("noscrollbar");', 600);
}

if (window.addEventListener) window.addEventListener('DOMMouseScroll', wheel, false);