public override bool UndoMethod(object obj)
 {
     TMain = new TrnMain
     {
         VoucherName   = "Purchase Invoice",
         VoucherPrefix = "PI"
     };
     if (ProdList != null)
     {
         ProdList.Clear();
     }
     TMain.PropertyChanged += TMain_PropertyChanged;
     NewShipment            = false;
     return(false);
 }
 private void TMain_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
 {
     if (e.PropertyName == "REFORDBILL")
     {
         TMain = new TrnMain
         {
             VoucherName   = "Purchase Invoice",
             VoucherPrefix = "PI",
             REFORDBILL    = TMain.REFORDBILL
         };
         if (ProdList != null)
         {
             ProdList.Clear();
         }
         TMain.PropertyChanged += TMain_PropertyChanged;
         _action = ButtonAction.Init;
     }
 }