Getting started with JTabbedPane

[wellab]

Here's the start of my application where I am trying to utilize the JTabbedPane class.

I want the frame to open with size 500x500 and
be a JTabbedPane. Why am I getting a constructor error right at the beginning? I don't see my error.

openPage.java [30:1] cannot resolve symbol
symbol : constructor openPage (java.lang.String)
location: class openPage
openPage OP = new openPage("Tool Inventory");
^
1 error

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
public class openPage extends JFrame
{
  //  JTabbedPane TP = new JTabbedPane();
    
    
    /** Creates a new instance of openPage */
    public openPage() 
    {
        this.setSize(500,500);
        this.setLocation(150,50);
        this.getContentPane().setLayout(new FlowLayout());
       // this.getContentPane().add(TP,"Tool Inventory");
        this.setVisible(true); 
        addWindowListener(new CloseWindow());
        
        
    }

    public static void main(String[] args)
    {
         //here is the error line
       openPage OP = new openPage("Tool Inventory");
       OP.pack();
       OP.show();
       
    }
    
    class CloseWindow extends WindowAdapter
    {
     public void windowClosing(WindowEvent event)
     {
         System.exit(0);
     }
    }
    
}