js url参数的获取和设置以及删除

//获取url参数的值：name是参数名

        function getQueryString(name) {
            var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
            var r = window.location.search.substr(1).match(reg);
            if (r != null) {
                return (r[2]);
            }
            return null;
        }

//设置url参数值，ref参数名,value新的参数值
        function changeURLPar(url, ref, value)
        {
            var str = "";
            if (url.indexOf('?') != -1)
                str = url.substr(url.indexOf('?') + 1);
            else
                return url + "?" + ref + "=" + value;
            var returnurl = "";
            var setparam = "";
            var arr;
            var modify = "0";

            if (str.indexOf('&') != -1) {
                arr = str.split('&');

                for (i in arr) {
                    if (arr[i].split('=')[0] == ref) {
                        setparam = value;
                        modify = "1";
                    }
                    else {
                        setparam = arr[i].split('=')[1];
                    }
                    returnurl = returnurl + arr[i].split('=')[0] + "=" + setparam + "&";
                }

                returnurl = returnurl.substr(0, returnurl.length - 1);

                if (modify == "0")
                    if (returnurl == str)
                        returnurl = returnurl + "&" + ref + "=" + value;
            }
            else {
                if (str.indexOf('=') != -1) {
                    arr = str.split('=');

                    if (arr[0] == ref) {
                        setparam = value;
                        modify = "1";
                    }
                    else {
                        setparam = arr[1];
                    }
                    returnurl = arr[0] + "=" + setparam;
                    if (modify == "0")
                        if (returnurl == str)
                            returnurl = returnurl + "&" + ref + "=" + value;
                }