Q: How to really end with the sessions I'm using Session to keep my login. I also, test it on every page_load i have, like this:  
if (Session["login"] != null)
{
    LbLogado.Text = "";
    LbLogado.Text += "Logado Com: " + Session["login"].ToString();
}
else
{
    Response.Redirect("~/login.aspx");
}

I also have a button exit, and this is the event: 
Session.Clear();
Response.Redirect("~/Login.aspx");

When I click on the exit button,I want to end with every session I have.
What is happening is, when I exit, and click on the browser to go back to the previous webpage it return normal to the page, but I want to redirect to the login.aspx page, because there is no sessions active.
I found some articles like this . But it's not my point.

A: Session.Abandon();
Response.Redirect("~/Login.aspx");


A: You should call:
Session.Abandon();

From MSDN:

Once the Abandon method is called, the current session is no longer valid and a new session can be started. Abandon causes the End event to be raised. A new Start event will be raised on the next request.


A: 
This should work in your case:

Session.Abandon();
Response.Redirect("~/Login.aspx");

