title: how do i make it possible for a window with buttons program to run?
body: <p>i have coded this program on an Eclipse development environment and i get only one error that says.</p>
  
  <p>"Error: Could not find or load main class incremental"</p>
  
  <p>please help.</p>
  
  <p>this is prototype for making a simple incremental game. </p>
  
  <pre><code>package pkIncremental;
  import javax.swing.*;
  import java.awt.Color;
  import java.awt.Font;
  import java.awt.event.*;
  public class Incremental extends JFrame implements ActionListener
  {
      public static void main(String[] args) 
      {
          new Incremental();
      }
      private JLabel lblHead1;
      private JLabel lblMessage;
      private JButton btnQuit;
      private JButton btnObtainMess;
      private JButton btnVis;
      private JButton btnNotVis;
  
      public Incremental()
      {
          this.setSize(600,500);
          this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          this.setTitle("Incremtial game!");
          this.setLayout(null);
          Font f = new Font("JSL Ancient", Font.ITALIC,24);
          final String M = "The points are bellow";
  
          lblHead1 = new JLabel (M);
          lblHead1.setBounds(150, 50, 200, 50);
          lblHead1.setFont(f);
          this.add(lblHead1);
  
          lblMessage = new JLabel("X");
          lblMessage.setOpaque(true);
          lblMessage.setBackground(Color.cyan);
          lblMessage.setBounds(100, 100, 300, 50);
          lblMessage.setFont(f);
          lblMessage.setForeground(Color.RED);
          this.add(lblMessage);
  
          btnObtainMess = new JButton("Click to get points.");
          btnObtainMess.setBounds(100, 150, 300, 50);
          btnObtainMess.setFont(f);
          btnObtainMess.addActionListener(this);
          this.add(btnObtainMess);
  
          btnNotVis = new JButton("not VIsible");
          btnNotVis.setBounds(100, 250, 150, 50);
          btnNotVis.setFont(f);
          btnNotVis.addActionListener(this);
          this.add(btnNotVis);
  
          btnVis = new JButton("Visible");
          btnVis.setBounds(250, 250, 150, 50);
          btnVis.setFont(f);
          btnVis.addActionListener(this);
          this.add(btnVis);
  
          btnQuit = new JButton("Quit");
          btnQuit.setBounds(440,380,100,50);
          btnQuit.setFont(f);
          btnQuit.addActionListener(this);
          this.add(btnQuit);
          this.setVisible(true);
      }
      public void actionPerformed(ActionEvent e)
      {
          String Mess = "Hello from the program";
          if (e.getSource() == btnObtainMess)
              lblMessage.setText(Mess);
          if (e.getSource() == btnVis)
              lblMessage.setForeground(Color.RED);
          if (e.getSource() == btnNotVis)
              lblMessage.setForeground(lblMessage.getBackground());
          if (e.getSource() == btnQuit)   
          System.exit(0);
      }
  }
  </code></pre>