js 设置|获取|删除 cookie|QueryString

//set cookie

function setCookie(c_name, value, expiredays) {

    var exdate = new Date();

    exdate.setDate(exdate.getDate() + expiredays);

    // 使设置的有效时间正确。增加toGMTString()

    document.cookie = c_name + "=" + escape(value) + ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString());

}



//get cookie

function getCookie(c_name) {

    if (document.cookie.length > 0) {

        c_start = document.cookie.indexOf(c_name + "=")

        if (c_start != -1) {

            c_start = c_start + c_name.length + 1;

            c_end = document.cookie.indexOf(";", c_start);

            if (c_end == -1) {

                c_end = document.cookie.length;

            }

            return unescape(document.cookie.substring(c_start, c_end));

        }

    }

    return null;

}



//delete coolie

function delCookie(name) {  

    var exp = new Date();

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

    var cval = getCookie(name);

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

}  



//get querystring

function getQueryValue(name) {

    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");

    var r = window.location.search.substr(1).match(reg);

    if (r != null)

        return unescape(r[2]);

    return "";

}