Press Enter and Click event fire on textbox

  txtSearch.Attributes.Add("onKeyPress", "javascript:if (event.keyCode == 13) __doPostBack('" + lbtnSearch.UniqueID + "','')");

Get the column value as per column name

DataBinder.Eval(e.Row.DataItem, "ColumnName")

Get Curent Page name without extension

Path.GetFileNameWithoutExtension(Request.RawUrl);

how to pass refrence variable

 int? i = 0;
pass in method  ----only below line
ref i

Check Cooki Enabled In Browser

protected void Page_Load(object sender, EventArgs e)
{
   if (!IsPostBack)
   {
     // Check if the browser supports cookies
     if (Request.Browser.Cookies)
     {
             if (Request.QueryString["CheckCookie"] == null)
            {
                   // Create the test cookie object
                   HttpCookie cookie = new HttpCookie("TestCookie", "1");
                   Response.Cookies.Add(cookie);
                  // Redirect to the same webform
                 Response.Redirect("Default.aspx?CheckCookie=1");
         }
         else
         {
            //Check the existence of the test cookie
            HttpCookie cookie = Request.Cookies["TestCookie"];
            if (cookie == null)
            {
              lblMessage.Text = "We have detected that, the cookies are disabled on your browser. Please enable cookies.";
            }
         }
      }
      else
      {
        lblMessage.Text = "Browser doesn't support cookies. Please install one of the modern browser's that support cookies.";
      }
   }
}