public static decimal?GetCustomerBalance(int customerID)
 {
     using (AprosysAccountingEntities db = new AprosysAccountingEntities())
     {
         var alpha = db.GetCustomerBalance(customerID).FirstOrDefault();
         if (alpha != null)
         {
             return(alpha.Balance);
         }
         else
         {
             return(0);
         }
     }
 }