private void Load_User()
        {
            int        _type     = Utils.CIntDef(ddlMenu.SelectedValue);
            List <int> listItems = (from a in db.USER_PERMISSIONs where a.PER_TYPE == _type select Utils.CIntDef(a.PER_USER, 0)).ToList();

            db = new AppketoanDataContext();
            var list = (from a in db.USERs
                        join b in db.GROUPs on a.GROUP_ID equals b.GROUP_ID
                        where (a.GROUP_ID != 1 && a.GROUP_ID != 2 && !listItems.Contains(a.USER_ID))
                        select new
            {
                a.USER_ID,
                a.GROUP_ID,
                namGroup = b.GROUP_NAME + " (" + a.USER_NAME + ")"
            }).OrderBy(n => n.USER_ID).OrderBy(n => n.GROUP_ID).ToList();

            if (list.Count > 0)
            {
                multiselect.DataSource     = list;
                multiselect.DataTextField  = "namGroup";
                multiselect.DataValueField = "USER_ID";
                multiselect.DataBind();
                multiselect.Multiple = true;
            }
        }
        private void Load_User()
        {
            int _type = Utils.CIntDef(ddlMenu.SelectedValue);
            List<int> listItems = (from a in db.USER_PERMISSIONs where a.PER_TYPE == _type select Utils.CIntDef(a.PER_USER, 0)).ToList();

            db = new AppketoanDataContext();
            var list = (from a in db.USERs
                        join b in db.GROUPs on a.GROUP_ID equals b.GROUP_ID
                        where (a.GROUP_ID != 1 && a.GROUP_ID != 2 && !listItems.Contains(a.USER_ID))
                        select new
                        {
                            a.USER_ID,
                            a.GROUP_ID,
                            namGroup = b.GROUP_NAME + " (" + a.USER_NAME + ")"
                        }).OrderBy(n => n.USER_ID).OrderBy(n => n.GROUP_ID).ToList();
            if (list.Count > 0)
            {
                multiselect.DataSource = list;
                multiselect.DataTextField = "namGroup";
                multiselect.DataValueField = "USER_ID";
                multiselect.DataBind();
                multiselect.Multiple = true;
            }
        }