title: Identifying the logged in user from different browser tab in asp.net
body: <p>I have a website with login option in asp.net.</p>
  
  <p>if i open website in two browser tabs and logged in with same user account and navigated to homescreen in both tabs , now i am  logged out from one tab and again logged in same tab,after that i clicked on the second tab,</p>
  
  <p>how can i discriminate that i am sending request from first tab or second tab from code behind?</p>
  
  <p>If the request is from second tab i need to navigate the application to login screen.How can i do this?</p>
  
  <p>in my home page i had added the logic like</p>
  
  <pre><code>if (Session["UserID"] == null)
  {
     Response.Redirect("Login.aspx");
  }
  </code></pre>
  
  <p>but the problem is that when i logout from first tab and login in again there, and after that second tab refreshed Session["UserID"] is not null so it will stay there.But i need to redirect login page .how can i achieve this??</p>