function EncodeCookie(InputString)
{
	var strRtn="";
	for (var i=InputString.length-1;i>=0;i--)
	{
		strRtn+=InputString.charCodeAt(i);
		if (i) strRtn+="a"; // 用 a 作分隔符
	}
	return strRtn;
}

// unicode 解码程序
function DecodeCookie(InputString)
{
	var strArr;
	var strRtn="";

	strArr=InputString.split("a");
	for (var i=strArr.length-1;i>=0;i=i-1)
		strRtn+=String.fromCharCode(eval(strArr[i]));
	return strRtn;
	
}

// 读 Cookie
function GetCookie(name)
{
	var strArg=name+"=";
	var nArgLen=strArg.length;
	var nCookieLen=document.cookie.length;
	var nEnd;
	var i=0;
	var j;
	while (i<nCookieLen)
	{
		j=i+nArgLen;
		if (document.cookie.substring(i,j)==strArg)
		{
			nEnd=document.cookie.indexOf (";",j);
			if (nEnd==-1) nEnd=document.cookie.length;
			if(document.cookie.substring(j,nEnd)=="")return null;
			return DecodeCookie(unescape(document.cookie.substring(j,nEnd)));
		}
		i=document.cookie.indexOf(" ",i)+1;
		if (i==0) break;
	}
	return null;
}

// 写 Cookie
function SetCookie(name,value,expires)
{
	var exp = new Date();
	exp.setTime(exp.getTime()+expires*60*60*1000);
	document.cookie=name+"="+escape(EncodeCookie(value))+";path=/;expires="+exp.toGMTString();
}