function changeOpac(opacity, id) {

    opacity = (opacity >= 100) ? 99.999 : opacity;

    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}

function blendimage(divid, imageid, imagefile, millisec, opacity) {

    var speed = Math.round(millisec / 20);

    if (opacity == 0) {

        document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";

        changeOpac(0, imageid);

        document.getElementById(imageid).src = imagefile;
    } else if (opacity >= 100) {

        changeOpac(100, imageid);

        document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";

        return;
    } else {

        changeOpac(opacity, imageid);
    }

    opacity = opacity + 5;

    setTimeout("blendimage('" + divid + "','" + imageid + "', '" + imagefile + "'," + millisec + "," + opacity + ");", speed);
}