Get querystring in javascript

function getParameterByName(name) {
    name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
    var regexS = "[\\?&]" + name + "=([^&#]*)";
    var regex = new RegExp(regexS);
    var results = regex.exec(window.location.search);
    if (results == null)
        return "";
    else
        return decodeURIComponent(results[1].replace(/\+/g, " "));
}

set and get cookies in javascript/C#

Using Javascript

function setCookie(c_name, value, exdays) {
    var exdate = new Date();
    exdate.setDate(exdate.getDate() + exdays);
    var c_value = escape(value) + ((exdays == null) ? "" : "; expires=" + exdate.toUTCString());
    document.cookie = c_name + "=" + c_value + "; path=/";

}

/*Get Cookie Value */
function getCookie(c_name) {
    var i, x, y, ARRcookies = document.cookie.split(";");
    for (i = 0; i < ARRcookies.length; i++) {
        x = ARRcookies[i].substr(0, ARRcookies[i].indexOf("="));
        y = ARRcookies[i].substr(ARRcookies[i].indexOf("=") + 1);
        x = x.replace(/^\s+|\s+$/g, "");
        if (x == c_name) {
            return unescape(y);
        }
    }
}

From .cs file

HttpCookie oCookie = (HttpCookie)HttpContext.Current.Request.Cookies["Cookiename"];
oCookie.Expires = DateTime.Now.AddHours(4);
oCookie.Value="123";
HttpContext.Current.Response.Cookies.Add(oCookie);

check browser in jquery

navigator.sayswho = (function () {
    var N = navigator.appName,
        ua = navigator.userAgent,
        tem;
    var M = ua.match(/(opera|chrome|safari|firefox|msie)\/?\s*(\.?\d+(\.\d+)*)/i);
    if (M && (tem = ua.match(/version\/([\.\d]+)/i)) != null) M[2] = tem[1];
    M = M ? [M[1], M[2]] : [N, navigator.appVersion, '-?'];
    return M;
})();