function getCookie(name)
{								// 使用名称参数取得Cookie值, null表示Cookie不存在
  var strCookies = document.cookie;
  var cookieName = name + "=";  // Cookie名称
  var valueBegin, valueEnd, value;
  // 寻找是否有此Cookie名称
  valueBegin = strCookies.indexOf(cookieName);
  if (valueBegin == -1) return null;  // 没有此Cookie
  // 取得值的结尾位置
  valueEnd = strCookies.indexOf(";", valueBegin);
  if (valueEnd == -1)
      valueEnd = strCookies.length;  // 最後一个Cookie
  // 取得Cookie值
  value = strCookies.substring(valueBegin+cookieName.length,valueEnd);
  return value;
}//end function getCookie

function saveCookie(name, value, expires, path, domain, secure)
{											// 保存Cookie
  var strCookie = name + "=" + value;
  if (expires){								// 计算Cookie的期限, 参数为天数
     var curTime = new Date();
     curTime.setTime(curTime.getTime() + expires*24*60*60*1000);
     strCookie += "; expires=" + curTime.toGMTString();
  }
  // Cookie的路径
  strCookie +=  (path) ? "; path=" + path : ""; 
  // Cookie的Domain
  strCookie +=  (domain) ? "; domain=" + domain : "";
  // 是否需要保密传送,为一个布尔值
  strCookie +=  (secure) ? "; secure" : "";
  document.cookie = strCookie;
}

function checkCookieExist(name)
{											// 检查Cookie是否存在
	if (getCookie(name))
		return true;
	else
		return false;
}//end function checkCookieExist

function deleteCookie(name, path, domain)
{											// 删除Cookie
	var strCookie;
	if (checkCookieExist(name))
	{										    // 设置Cookie的期限为己过期
		strCookie = name + "="; 
		strCookie += (path) ? "; path=" + path : "";
		strCookie += (domain) ? "; domain=" + domain : "";
		strCookie += "; expires=Thu, 01-Jan-70 00:00:01 GMT";
		document.cookie = strCookie;
	}//end if
}//end function deleteCookie