Redirect Loop Error

Hi,
I have created a login page, and for this login page for different user, it will go to different page for e.g admin will to admin page, and normal user will access the user page. the error will occur when i creating a new user in the admin page, or after i log out from the admin page and wants to access the normal user page.

below are my codes and error



login page code

protected void Page_Load(object sender, EventArgs e)
        {
            Label1.Visible = false;
            if (this.Request.IsAuthenticated)
            {
                Response.Redirect("~/Login/Default2.aspx");
    & ...