//取得最後一次結帳的年月
 public string GetLastCheckMonth()
 {
     try
     {
         string strResult = string.Empty;
         DBO.VDM_VendorAgmDBO dbo = new VDM_VendorAgmDBO(ref USEDB);
         DataTable dt = dbo.GetLastCheckMonth();
         strResult = dt.Rows[0]["check_month"].ToString();
         return strResult;
     }
     catch (Exception ex)
     {
         throw ex;
     }
 }