public bool AddActivityLog(int userID, DateTime date)
 {
     try
     {
         int discount = 0;
         UserActivityLog log = new UserActivityLog();
         if (log.GetLastActivityByUserID(userID))
         {
             // get between days only i.e.
             // last day 01/03/2015 - current date  04/03/2015
             // the between days not equal 3 it's only 2 ( 02/03/2015 - 03-03-2015 )
             // so diff = current date - last date - 1
             discount = date.Subtract(log.Date).Days - 1;
         }
         log.AddNew();
         log.ComboUserID = userID;
         log.Date = date;
         log.DaysToDiscount = discount;
         log.Save();
         // if save success
         return true;
     }
     catch (Exception ex)
     {
         //if save fail - duplicate entry
         return false;
     }
 }