new updated

app/src/main/java/com/example/yourcashiertest/activities/PaymentActivity.java

@@ -73,11 +73,16 @@ public class PaymentActivity extends AppCompatActivity {
             ViewUtil.showMessage(view, "Please choose type payment");
         } else {
             int amountPaid = Integer.parseInt(binding.etAmountPaid.getText().toString());
+            if ( amountPaid < amount) {
+                ViewUtil.showMessage(view, "AmountPaid doesn't less than total price");
+            } else {
                 refund = amountPaid - amount;
                 startActivity(new Intent(PaymentActivity.this, StatusPayment.class).putExtra(REFUND, refund).putExtra(PAY_WITH, payment));
                 cartViewModel.clear();
                 finish();
             }
+
+        }
     }