// Step 1: Import the package classes
import javax.swing.*;

public class MyFirstGUI extends JFrame/*Step2*/{
   
    public static void main(String args[]){
        
        // Step 3: Instantiate an instance
        MyFirstGUI yonghui= new MyFirstGUI();
        
        // Step 4: Set the properties
        yonghui.setSize(300,400);
        yonghui.setVisible(true);
       
    }//end main
    
    
}//end class