function chg_menu(str, strers)
{
  var tary = strers.split(",");
  for (i = 0; i < tary.length; i ++)
  {
    if (tary[i] == str)
    {
      document.getElementById(tary[i]).src ="/images/"+ tary[i] + "_b.jpg";
      document.getElementById("area_" + tary[i]).style.display = '';
    }
    else
    {
      document.getElementById(tary[i]).src ="/images/"+ tary[i] + ".jpg";
      document.getElementById("area_" + tary[i]).style.display = 'none';
    }
  }
}