String.prototype.trimEnd = function (c) {
    if (c)
        return this.replace(new RegExp(c.escapeRegExp() + "*$"), '');
    return this.replace(/\s+$/, '');
};
String.prototype.trimStart = function (c) {
    if (c)
        return this.replace(new RegExp("^" + c.escapeRegExp() + "*"), '');
    return this.replace(/^\s+/, '');
};

String.prototype.escapeRegExp = function () {
    return this.replace(/[.*+?^${}()|[\]\/\\]/g, "\\$0");
};

getUrlEncodedKey = function (key, query) {
    if (!query)
        query = window.location.search;
    var re = new RegExp("[?|&]" + key + "=(.*?)&");
    var matches = re.exec(query + "&");
    if (!matches || matches.length < 2)
        return "";
    return decodeURIComponent(matches[1].replace("+", " "));
};

setUrlEncodedKey = function (key, value, query) {

    query = query || window.location.search;
    var q = query + "&";
    var re = new RegExp("[?|&]" + key + "=.*?&");
    if (!re.test(q))
        q += key + "=" + encodeURI(value);
    else
        q = q.replace(re, "&" + key + "=" + encodeURIComponent(value) + "&");
    q = q.trimStart("&").trimEnd("&");
    return q[0] == "?" ? q : q = "?" + q;
};