// roll over
function chgImg(arg_img, arg_src) {
    document.images[arg_img].src = arg_src;
  }

// open window
function openWin(arg_url, arg_name, arg_width, arg_height, arg_scroll, arg_resize) {
  var win = window.open(arg_url,arg_name,'scrollbars=' + arg_scroll + ',resizable=' + arg_resize + ',width=' + arg_width +  ',height=' + arg_height);
}

// close window
function closeWin() {
  window.close();
}