function gross(v_nr) {

        for (i=0; i<v_width.length; i++ ) {
             v_div = document.getElementById("grimg"+i);
                if (i == v_nr) {
                   v_div.style.width = v_width[i]+"px";
                   v_div.style.height = v_height[i]+"px";
                   v_div.style.visibility = "visible";
                } else {
                   v_div.style.visibility = "hidden";
                   v_div.style.width = "0px";
                   v_div.style.height = "0px";
                }
        }
}