how to end a session in asp .net?

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C#

C#4.0

Hello, I have two webforms one is login page and another is home page. Whenever i clicks on logout button in "home page" it redirects to "login page" and if i clicks on "back" button in browser it redirects to home page which shouldn't be happened. Now my query is that whenever i would click "back" button in browser(after logging out from home page)it would redirect to login page rather than home page. Thanks........

LogIn Page Code:

try
        {
            Session["ename"] = TextBox1.Text;
            cn.Open();
            SqlCommand SqlCmd = new SqlCommand("SELECT * FROM empregd WHERE ename='" + TextBox1.Text + "' AND password='" + TextBox2.Text + "'", cn);
            SqlDataAdapter SqlDa = new SqlDataAdapter(SqlCmd);
            SqlDataReader SqlDr = SqlCmd.ExecuteReader();
            if (SqlDr.Read())
            {
                Response.Redirect("http://localhost:49871/WebSite7/Default6.aspx");
            }
            SqlDr.Close();
            cn.Close();
            TextBox1.Text = "";
            TextBox2.Text = "";
        }
        catch (Exception ex)
        {
            throw ex;
        }

HomePage Code

protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            if (Session["ename"]== null)
            {
                Response.Redirect("http://localhost:49871/WebSite7/Default5.aspx");
            }
            Label2.Text = Session["ename"].ToString();
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        try
        {
            Response.Redirect("http://localhost:49871/WebSite7/Default5.aspx");
            FormsAuthentication.SignOut();
            Session.Abandon();
            Session.Clear();
            Session["ename"] = null;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }