function expand_div(obj){
    var d = obj.parentNode.parentNode.parentNode;    
    var img_down    = new Image();
    var img_up      = new Image();
    
    img_down.src    = "images/res/arrow_norm_down.png";
    img_up.src      = "images/res/arrow_norm_up.png";
    
    if (d.style.height=="auto") {
        d.style.height = "70px";
        d.childNodes[1].childNodes[3].firstChild.firstChild.src = img_down.src;
    }
    else
    {
        d.style.height = "auto";
        d.childNodes[1].childNodes[3].firstChild.firstChild.src = img_up.src;
    }
}