function refresh (cookie_name1,cookie_name2,cookie_name3,cookie_name4,cookie_name5,cookie_name6,cookie_name7)
{
  var cookie_date = new Date ( );  // current date & time
  cookie_date.setTime ( cookie_date.getTime() - 1 );
  document.cookie = cookie_name1 += "=; expires=" + cookie_date.toGMTString();
  document.cookie = cookie_name2 += "=; expires=" + cookie_date.toGMTString();
  document.cookie = cookie_name3 += "=; expires=" + cookie_date.toGMTString();
  document.cookie = cookie_name4 += "=; expires=" + cookie_date.toGMTString();
  document.cookie = cookie_name5 += "=; expires=" + cookie_date.toGMTString();
  document.cookie = cookie_name6 += "=; expires=" + cookie_date.toGMTString();
  document.cookie = cookie_name7 += "=; expires=" + cookie_date.toGMTString();
}