//cookie的相关函数

function GetCookieVal(offset)
//获得Cookie解码后的值
{
    var endstr = document.cookie.indexOf (";", offset);
    if (endstr == -1)
    endstr = document.cookie.length;
    return unescape(document.cookie.substring(offset, endstr));
}

function SetCookie(name, value)
//设定Cookie值
{
    var expdate = new Date();
    var argv = SetCookie.arguments;
    var argc = SetCookie.arguments.length;
    var expires = (argc > 2) ? argv[2] : null;
    var path = (argc > 3) ? argv[3] : "/";
    var domain = (argc > 4) ? argv[4] : "1b2g.com";
    var secure = (argc > 5) ? argv[5] : false;
    if(expires!=null) expdate.setTime(expdate.getTime() + ( expires * 1000 ));
    document.cookie = name + "=" + escape (value) +((expires == null) ? "" : ("; expires="+ expdate.toGMTString()))+((path == null) ? "" :("; path=" + path)) +((domain == null) ? "" : ("; domain=" + domain))+((secure == true) ? "; secure" : "");
}

function DelCookie(name)
//删除Cookie
{
    var exp = new Date();
    exp.setTime (exp.getTime() - 1);
    var cval = GetCookie(name);
    document.cookie = name + "=" + cval + "; expires="+ exp.toGMTString();
}

function GetCookie(name)
//获得Cookie的原始值
{
    var arg = name + "=";
    var alen = arg.length;
    var clen = document.cookie.length;
    var i = 0;
    while (i < clen)
    {
        var j = i + alen;
        if (document.cookie.substring(i, j) == arg)
        return GetCookieVal(j);
        i = document.cookie.indexOf(" ", i) + 1;
        if (i == 0) break;
    }

    return null;
}