I keep getting API restrictions and errors with this code....could someone help me fix it or something?

package sample;

import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.geometry.*; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.scene.control.Label; import javafx.geometry.Insets; import javafx.geometry.Pos; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.TextField; import javafx.scene.layout.GridPane; import javafx.stage.Stage;

public class TipTaxandTotal extends Application {

public void start(Stage primaryStage) throws Exception{ primaryStage.setTitle("Calculator");

GridPane rootNode = new GridPane(); rootNode.setPadding(new Insets(15)); rootNode.setHgap(5); rootNode.setVgap(5); rootNode.setAlignment(Pos.CENTER);

Scene myScene = new Scene(rootNode, 300, 200);

rootNode.add(new Label("Amount:"), 0, 0); TextField firstValue = new TextField(); rootNode.add(firstValue, 1, 0); rootNode.add(new Label("Toatal is:"), 0, 5); Button aButton = new Button("Calculate"); rootNode.add(aButton, 1, 2); GridPane.setHalignment(aButton, HPos.LEFT); TextField result = new TextField(); result.setEditable(false); rootNode.add(result, 1, 5); TextField tax = new TextField(); rootNode.add(new Label("Tax:"), 0, 3); tax.setEditable(false); rootNode.add(tax,1,3); TextField tip = new TextField(); rootNode.add(new Label("Tip:"), 0, 4); tip.setEditable(false); rootNode.add(tip,1,4);

aButton.setOnAction(e -> { Float value1 = Float.valueOf(firstValue.getText());

Float value2 =(value1*18)/100; Float value3 = (value1*7)/100; Float r = value1+value2+value3 ; tax.setText(value3.toString()); tip.setText(value2.toString()); result.setText(r.toString()); });

primaryStage.setScene(myScene);

primaryStage.show(); }

public static void main(String[] args) { launch(args); } }