implementing asp.net login and logout 
<p>I have created a simple login page for asp.net which takes in user name and password in text boxes and compare it with the one I have stored in database and redirects only if it is same as stored in database.</p>

<p>But what is happening is that when I login and then go back by pressing back button, then again pressing forward button of browser,it is still redirecting users.</p>

<p>So can anyone help with this issue as to as once logged out,it should redirect only after entering credentials and not by pressing forward button of the browser.</p>

<pre><code>protected void LoginButton_Click(object sender, EventArgs e)
    {
        int results = 0;
        if (txtUsername.Text != "" &amp;&amp; txtPassword.Text != "")
        {
            results = Validate_Login(txtUsername.Text, txtPassword.Text);
        }
        else
        {
            lblMessage.Text = "Please make sure that the username and the password is Correct";
        }
        if (results == 1)
        {
            if (txtUsername.Text.Equals("admin"))
            {
                Response.Redirect("~/ConfigurationPage.aspx");
            }
            else
            {
                Response.Redirect("");
            }
        }
        else
        {
            lblMessage.Text = "Invalid Login";
            lblMessage.ForeColor = System.Drawing.Color.Red;
        }
    }

    public int Validate_Login(String username, String password)
    {
        var conString = ConfigurationManager.ConnectionStrings["ConnectionString"];
        string strConnString = conString.ConnectionString;
        int results = 0;

        using (SqlCommand cmdselect = new SqlCommand
                                   {
                                       CommandType = CommandType.StoredProcedure,
                                       CommandText = "[dbo].[prcLoginv]"
                                   })
        {

            cmdselect.Parameters.Add("@Username", SqlDbType.VarChar, 50).Value = username;
            cmdselect.Parameters.Add("@UPassword", SqlDbType.VarChar, 50).Value = password;
            cmdselect.Parameters.Add("@OutRes", SqlDbType.Int, 4);

            cmdselect.Parameters["@OutRes"].Direction = ParameterDirection.Output;



            try
            {
                if (connection == null)
                {
                    connection = new SqlConnection(strConnString);
                    connection.Open();
                    cmdselect.Connection = connection;
                    cmdselect.ExecuteNonQuery();
                    results = (int) cmdselect.Parameters["@OutRes"].Value;
                }
                else if (connection.State == ConnectionState.Closed)
                {
                    connection.Open();
                    cmdselect.ExecuteNonQuery();
                    results = (int) cmdselect.Parameters["@OutRes"].Value;
                }

            }
            catch (SqlException ex)
            {
                lblMessage.Text = ex.Message;
            }
            finally
            {
                if (connection != null)
                {
                    connection.Close();
                }
            }
        }
        return results;
    }
</code></pre>
