rollback transaction
raiserror ('Плохо Бро,хочешь что бы твой отпуск закончился раньше чем ты устроился или позже чем уволил', 16, -1)
return 

try
              ADOCommand1.Execute;
          except
              if dm.ADOConnection1.Errors.Count < 1 then Exit;
              for i:=0 to dm.ADOConnection1.Errors.Count-1 do
                  begin
                    case dm.ADOConnection1.Errors[i].NativeError  of
                        2627: MessageDlg ('Такая дата уже существует в базе, будте внимательны ;-)', mtError, [mbOK], 0);
                        else  MessageDlg (dm.ADOConnection1.Errors[i].Source+' '+dm.ADOConnection1.Errors[i].Description, mtError, [mbOK], 0);
                    end;
                  end;
          end;

  try
    ADOCommand1.Execute;
  except
    on e: Exception do MessageBox(e.Message)
  end;

procedure TAddVocationForm.cxButton2Click(Sender: TObject);
var
QuaryStr1,QuaryStr2: String;
colday, i: integer;
saly: real;
begin
ValiDataForm;
colday:=DaysBetween(cxDateEdit2.Date,cxDateEdit3.Date);
    with ComboBox1 do
    begin
      saly:=(TEmpl(Items.Objects[ItemIndex]).avesal/29.7)*colday;
      QuaryStr1:=EmptyStr;
      QuaryStr2:=EmptyStr;
      QuaryStr1:='insert into vocation (idemployee';
      QuaryStr2:=' values('+IntToStr(TEmpl(Items.Objects[ItemIndex]).id);
      if Trim(cxTextEdit1.Text)<>'' then
      begin
          QuaryStr1:=QuaryStr1+',ordernum';
          QuaryStr2:=QuaryStr2+','''+Trim(cxTextEdit1.Text)+'''';
      end;
      if cxDateEdit1.Text<>'' then
      begin
          QuaryStr1:=QuaryStr1+',orderdate';
          QuaryStr2:=QuaryStr2+','''+DateToStr(cxDateEdit1.Date,myformat)+'''';
      end;
          QuaryStr1:=QuaryStr1+',datestart';
          QuaryStr2:=QuaryStr2+','''+DateToStr(cxDateEdit2.Date,myformat)+'''';
          QuaryStr1:=QuaryStr1+',dateend';
          QuaryStr2:=QuaryStr2+','''+DateToStr(cxDateEdit3.Date,myformat)+'''';
          QuaryStr1:=QuaryStr1+',vocdays';
          QuaryStr2:=QuaryStr2+','+IntToStr(colday);
          QuaryStr1:=QuaryStr1+',paiddays';
          QuaryStr2:=QuaryStr2+','+IntToStr(colday);
          QuaryStr1:=QuaryStr1+',vacationsum)';
          QuaryStr2:=QuaryStr2+','+StringReplace(FloatToStr(saly),',','.',[])+')';
    end;
    ADOCommand1.CommandText:=EmptyStr;
    ADOCommand1.CommandText:=QuaryStr1+QuaryStr2;
    Application.MessageBox(PAnsiChar(QuaryStr1+QuaryStr2),'Worning',0);
    try
        ADOCommand1.Execute;
    except
        on e: Exception do MessageBox(e.Message);
    end;
    VocationForm.ADODataSet1.Requery;
end; 

 on e: Exception do MessageBox(e.Message);

    try
        ADOCommand1.Execute;
    except
        on e: Exception do  Application.MessageBox(PAnsiChar(e.Message),'Worning',0);
    end;

          try
              ADOCommand1.Execute;
          except
              if dm.ADOConnection1.Errors.Count < 1 then Exit;
              for i:=0 to dm.ADOConnection1.Errors.Count-1 do
                  begin
                    case dm.ADOConnection1.Errors[i].NativeError  of
                        2627: MessageDlg ('Такая дата уже существует в базе, будте внимательны ;-)', mtError, [mbOK], 0);
                        else  MessageDlg (dm.ADOConnection1.Errors[i].Source+' '+dm.ADOConnection1.Errors[i].Description, mtError, [mbOK], 0);
                    end;
                  end;
          end;