ASP.NET

FormsAuthentication.SetAuthCookie(
           "jhon", false);

       FormsAuthenticationTicket ticket1 =
          new FormsAuthenticationTicket(
               1,                                   // version
               "jhon",   // get username  from the form
               DateTime.Now,                        // issue time is now
               DateTime.Now.AddMinutes(10),         // expires in 10 minutes
               false,      // cookie is not persistent
               "Admin"                              // role assignment is stored
           // in userData
               );
       HttpCookie cookie1 = new HttpCookie(
         FormsAuthentication.FormsCookieName,
         FormsAuthentication.Encrypt(ticket1));
       Response.Cookies.Add(cookie1);

       Response.Redirect("Default.aspx");

if (HttpContext.Current.User != null)
        {
            if (HttpContext.Current.User.Identity.IsAuthenticated)
            {
                FormsIdentity id = (FormsIdentity)HttpContext.Current.User.Identity;
                FormsAuthenticationTicket ticket = id.Ticket;

                string userData = ticket.UserData;
                string[] roles = userData.Split(',');
                HttpContext.Current.User = new GenericPrincipal(id, roles);
            }
        }

<br />
int presentCount = 0;<br />
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)<br />
{<br />
if (e.Row.RowType == DataControlRowType.DataRow)<br />
{<br />
//if ( # = "P")<br />
presentCount++;<br />
}<br />
else if (e.Row.RowType == DataControlRowType.Footer)<br />
{<br />
e.Row.Cells[3].Text = presentCount.ToString();<br />
}<br />
}