public static string update_(Ungluong ul, string thang, string nam)
 {
     return(DAO_Ungluong.update_(ul, thang, nam));
 }
 // update
 public static string update(Ungluong ulc, Ungluong ul)
 {
     return(DAO_Ungluong.update(ulc, ul));
 }
 // insert ung luong
 public static string insert(Ungluong ul)
 {
     return(DAO_Ungluong.insert(ul));
 }
 // kiem tra trung truoc khi them
 public static bool kt_trung_them(Ungluong ul)
 {
     return(DAO_Ungluong.kt_trung_them(ul));
 }
 // select ung luong theo ma nv
 public static DataTable select(string manv)
 {
     return(DAO_Ungluong.select(manv));
 }