convert Numbers to aphabets Useful for Excel

 static string CharacterIncrement(int colCount)
    {
        int TempCount = 0;
        string returnCharCount = string.Empty;

        if (colCount < 26)
        {
            TempCount = colCount;
            char CharCount = Convert.ToChar((Convert.ToInt32('A') + TempCount));
            returnCharCount += CharCount;
            return returnCharCount;
        }
        else
        {
            var rev = 0;

            while (colCount >= 26)
            {
                colCount = colCount - 26;
                rev++;
            }

            returnCharCount += CharacterIncrement(rev - 1);
            returnCharCount += CharacterIncrement(colCount);
            return returnCharCount;
        }
    }

Remember Me

Code Behind:
 HttpCookie Cookie = new HttpCookie("Login");
                    if (cbRemember.Checked)
                    {
                        Cookie.Values.Add("UserName", user.Value);
                        Cookie.Values.Add("Password", pwd.Value);
                        Cookie.Values.Add("RememberMe", "1");
                        Cookie.Expires = DateTime.Now.AddDays(60);
                    }
                    else
                    {
                        HttpContext.Current.Request.Cookies.Remove("Login");
                        Cookie.Expires = DateTime.Now.AddDays(-10d);
                    }
                    Response.Cookies.Add(Cookie);

Javascript

function fnCookie() {
                if (document.cookie && document.cookie != null) {

                    var cookies = document.cookie;
                    cookies = cookies.substring(6);
                    var cookiArry = cookies.split('&');

                    for (i = 0; i < cookiArry.length; i++) {
                        if (i == 0) {
                            $("#ctl00_user").val(cookiArry[i].substring(9));
                        }
                        if (i == 1) {
                            $("#ctl00_pwd").val(cookiArry[i].substring(9));
                        }
                        if (i == 2) {
                            var rem = cookiArry[i].substring(11);
                            if (rem == 1)
                                $("#ctl00_cbRemember").attr('checked', true);
                            else
                                $("#ctl00_cbRemember").attr('checked', false);
                        }
                    }
                }
            }
 or
 Code Behind:
if(!isPostback)
{
  HttpCookie myCookie = Request.Cookies["Login"];
                if (myCookie != null)
                {
                    this.user.Value = myCookie["UserName"];
                    PassWord.Value = myCookie["Password"];
                    ScriptManager.RegisterStartupScript(this, GetType(), System.Guid.NewGuid().ToString(), "fnSetPWD();", true);
                    cbRemember.Checked = Convert.ToBoolean(int.Parse(myCookie["RememberMe"].ToString()));
                }
}

Log off when you close the browser

 /*in master page Javascript*/

        $(document).ready(function() {
            debugger;
            var hdf = $('#ctl00_hdflog').val();
            if (hdf == '1') {
                $('body').attr("onunload", "javascript:removesessions();");
            }
        });

        function removesessions() {
            $.ajax({
                url: window.location.href + (window.location.href.toString().indexOf('?') > -1 ? '&close=force' : '?close=force'),
                async: false
            });
        }

/*You need a hidden field */
<input type="hidden" runat="server" id="hdflog" value="0" />
  
  /*Cs file on page load*/
            if (Request.QueryString["close"] != null && Request.QueryString["close"] == "force")
            {
                FormsAuthentication.SignOut();
                Session.Abandon();
                Session.Clear();
                Response.Cache.SetCacheability(HttpCacheability.NoCache);
                Response.Cache.SetAllowResponseInBrowserHistory(false);
            }

Text Box allowing only alphabets

<asp:TextBox runat="server" ID="txtFirstName" onkeypress="javascript:return CheckText(event.keyCode);"></asp:TextBox>

function CheckText(evt) {
            var keyCode = (evt.which) ? evt.which : event.keyCode
            if (keyCode == 8 || (keyCode >= 65 && keyCode <= 122)) {
                return true;
            }
            return false;
        }