function GetCookie (name)
  {
  var start = document.cookie.indexOf (name + "=");
  var len = start + name.length + 1;
  if ((!start ) && (name != document.cookie.substring (0, name.length)))
    return null;
  if (start == -1)
    return null;
  var end = document.cookie.indexOf (';', len);
  if (end == -1)
    end = document.cookie.length;
  return (unescape (document.cookie.substring (len, end)));
  }

function SetCookie (name, value, days)
  {
	var today = new Date();
	if (!days)
	  days = 7;
  var expires = days * 60 * 60 * 24 * 1000;
  var expires_date = new Date (today.getTime() + expires);
	var expires_string = expires_date.toGMTString();
  document.cookie = name + '=' + escape (value) + ';path=/' + ';expires=' + expires_string;
  }

function DeleteCookie (name, path, domain)
  {
  if (GetCookie (name))
    document.cookie = name + '=' +
      ((path)   ? ';path='   + path   : '' ) +
      ((domain) ? ';domain=' + domain : '' ) +
      ';expires=Thu, 01-Jan-1970 00:00:01 GMT';
  }