Insert (Save) QueryString value into database in ASP.Net using C#

how to insert value from QueryString using asp c#

i passed http://localhost:21566/Default.aspx?empid=7221 from index.aspx to Default.aspx.

I want to save empid value in table where table column is lst_updated_by.

protected void Save(object sender, EventArgs e)
{
    Response.Redirect("Default.aspx?empid=" + Session["empid"].ToString().Trim());
}