import java.awt.*;
import java.awt.event.*;
public class TestJavaApplication extends Frame implements ActionListener{
Label l1;
TextField t1;
Button b1;
public TestJavaApplication () {
super();
setSize(300,100);
setLayout(null);
l1 = new Label("please type number:");
l1.setBounds(50,30,200,20);
Font f1 = new Font("Dialog",Font.BOLD, 14);
l1.setFont(f1);
add(l1);
t1 = new TextField("10");
t1.setBounds(50,60,200,20);
add(t1);
b1 = new Button("OK");
b1.setBounds(100,100,100,25);
add(b1);
b1.addActionListener(this);
}
public static void main(String args[]) {
TestJavaApplication f = new TestJavaApplication();
f.show();
}
public void actionPerformed(ActionEvent e) {
String s = t1.getText();
int n = Integer.parseInt(s);
int m = 0;
for (int i = 1; i <= n; i++)
m += i;
s = Integer.toString(m);
l1.setText("total: " + s);
}
}