用JavaScript操作cookie

function Setcookie (name, value) { //设置名称为name,值为value的Cookie
var argc = SetCookie.arguments.length;
var argv = SetCookie.arguments;
var path = (argc > 3) ? argv[3] : null;
var domain = (argc > 4) ? argv[4] : null;
var secure = (argc > 5) ? argv[5] : false;


documents.cookie = name + "=" + value +
((path == null) ? "" : ("; path=" + path)) +
((domain == null) ? "" : ("; domain=" + domain)) +
((secure == true) ? "; secure" : "");
}

function Deletecookie (name) { //删除名称为name的Cookie
var exp = new Date();
exp.setTime (exp.getTime() - 1);
var cval = GetCookie (name);
documents.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}
function Clearcookie() //清除COOKIE
{
var temp=documents.cookie.split(";");
var loop3;
var ts;
for (loop3=0;loop3 {
ts=temp[loop3].split("=")[0];
if (ts.indexOf(’mycat’)!=-1)
DeleteCookie(ts); //如果ts含“mycat”则执行清除
}
}

function getCookieVal (offset) { //取得项名称为offset的cookie值
var endstr = documents.cookie.indexOf (";", offset);
if (endstr == -1)
endstr = documents.cookie.length;
return unescape(documents.cookie.substring(offset, endstr));
}

function GetCookie (name) { //取得名称为name的cookie值
var arg = name + "=";
var alen = arg.length;
var clen = documents.cookie.length;
var i = 0;
while (i < clen) {
var j = i + alen;
if (documents.cookie.substring(i, j) == arg)
return getCookieVal (j);
i = documents.cookie.indexOf(" ", i) + 1;
if (i == 0) break;
}
return null;
}