logout action problem in IE

I have a login page and a default page to be redirected to after login. when I clicked on thew logout button in the default page it correctly redirects to login page. But when I click the back button in the IE I can again see the protected default page( in mozilla everythng is OK, no problem but in IE this problem occurs).


Have I done something wrong. My code r below:
login page===========


protected void Login1_LoggedIn(object sender, EventArgs e)
        {
            if (Roles.IsUserInRole(Login1.UserName, "Members")) {
               Response.Redirect("users/Member/default.aspx");
                //Server.Transfer("users/Member/default.aspx",true);
&nb ...