private async void Button_Clicked(object sender, EventArgs e)
        {
            var transactionCore = new TransactionCore();

            if (type.SelectedItem != null && status.SelectedItem != null && amount.Text != null &&
                subCat.SelectedItem != null && from.Text != null && date.Date != null)
            {
                int typeId   = types.Where(t => t.Key == type.SelectedItem.ToString()).FirstOrDefault().Value;
                int statusId = statuses.Where(t => t.Key == status.SelectedItem.ToString()).FirstOrDefault().Value;
                int subCatId = subCats.Where(t => t.Key == subCat.SelectedItem.ToString()).FirstOrDefault().Value;

                int result = await transactionCore.CreateTransaction(des.Text, from.Text, float.Parse(amount.Text), date.Date.ToString(), accountId, typeId, statusId, subCatId);

                if (result != -1)
                {
                    await DisplayAlert("Failed", "Account not added", "OK");
                }
                else
                {
                    await DisplayAlert("Success", "Account has been added", "OK");

                    await Navigation.PopAsync();
                }
            }
            else
            {
                await DisplayAlert("Failed", "Account not added", "OK");
            }
        }