title: Unable to clear session completely
body: <p>I am working on an application in ASP.NET with c# and MSSQL DB. I am using a simple logic that if the session variables contain appropriate values then a page should open otherwise it should redirect to the login page. This is the code thats working.</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
          {
              if(Session["loggedinloginid"]==null || Session["loggedinpassword"]==null)
                  Response.Redirect("login.aspx");
  
              con.ConnectionString = ConfigurationManager.ConnectionStrings["familyConnectionString"].ConnectionString;
              con.Open();
              adp = new SqlDataAdapter("select * from admins where loginid=N'" + Session["loggedinloginid"].ToString() + "' AND password=N'" + Session["loggedinpassword"].ToString() + "'", con);
              dt = new DataTable();
              adp.Fill(dt);
  
              if (dt.Rows.Count == 0)
                  Response.Redirect("login.aspx");
  
              LinkButton lb=(LinkButton)(Master.FindControl("LinkButton1"));
              lb.Text = "Welcome " + Session["loggedinloginid"].ToString()+"| Log Out |";
              lb.Click += new EventHandler(lb_Click);
          }
  
          void lb_Click(object sender, EventArgs e)
          {
              Session.Clear();
              Response.RedirectPermanent("WebForm2.aspx");
              //throw new NotImplementedException();
          }
  </code></pre>
  
  <p>The problem is that when I log out and clear the session and type the URL of the page in the browser that I want to protect (the page with this code), it opens! Why and how can I avoid this?</p>