//添加cookie值

function addcookie(name, value, days) {

    days = days || 0;

    var expires = "";

    if (days != 0)

        var date = new Date();

        date.setTime(date.getTime() + (days * 24 * 3600 * 1000));

        expires = "; expires=" + date.toGMTString();

    }

    document.cookie = name + "=" + escape(value) + expires + "; path=/";

}

//获取cookie值

function getcookie(name) {

    var strcookie = document.cookie;

    var arrcookie = strcookie.split("; ");

    for (var i = 0; i < arrcookie.length; i++) {

        var arr = arrcookie[i].split("=");

        if (arr[0] == name)

            return arr[1];

    }

    return "";

}

//删除cookie值

function delCookie(name) {

    var exp = new Date();

    exp.setTime(exp.getTime() - 1);

    var cval = getcookie(name);

    if (cval != null)

        document.cookie = name + "=" + cval + "; path=/;expires=" + exp.toGMTString();

}

<div id="cookie"></div>

//添加一个名为name的cookie值

addcookie("name","123456456");

//获取一个名为name的cookie值

var name = getcookie("name");

//获取页面id名为cookie的标签

var text = document.getElementById("cookie");

//将页面id名为cookie的标签的innerHTML的内容改为name所对应的值

text.innerHTML=name;

//延时五秒后 删除一个名为name的cookie值

setTimeout(function(){

    delCookie("name");

},5000);