EditarUsuarios.CargarRolesUser C# (CSharp) Method

    protected void CargarRolesUser()
    {
        try
        {
            lb_userrols.Items.Clear();
            lb_userrols.DataSource = USER.RetrieveRolUser(cmb_empleados.SelectedValue);
            lb_userrols.DataBind();
            CargarRolesSys();
        }
        catch (Exception er)
        {
            Session["Error_Msg"] = er.Message;
            Response.Redirect("~/Error.aspx", true);
        }
    }