GUI not appearing when i run file?

[Basskiddanny]

First of all i will let you know that i am using the NetBeans IDE 5.0

I have part written a program that will allow a user to store information about the company cars, it will store a range of data, but i have hit a snag. When i build my main project, it builds successfully, but the GUI does not appear on screen.

I tried going to "Run" and then "frmCars.java", at the bottom in the output window it says it was done successfully, but i do not see the GUI on screen?

I don't want people to do the work for me, but i would like some advice on why it is not showing the GUI, as i was just about to test the "New" button to make sure it successfully creates the file.

At the minute i have 3 documents:

Main.java
carRecords.java (class)
frmCars (form/gui)

code for Main.java

package carcalculator;

/**
 *
 * @author Daniel
 */
public class Main {
    
    /** Creates a new instance of Main */
    public Main() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
    }
    
}

code for carRecords.java

package carcalculator;

/**
 *
 * @author Daniel Harris
 */
import java.io.*;
public class carRecords implements Serializable{
    
    private String regNo;
    private String description;
    private double runningCost;
    private float annualInsurance;
    private String department;
    
    /** Creates a new instance of VideoRecord */
    public carRecords() {
        this("","",0,0,"");
    }
    
    public carRecords(String r, String d,double c,float i,String m){
        setRegNo(r);
        setDescription(d);
        setRunningCost(c);
        setAnnualInsurance(i);
        setDepartment(m);
    }
    
    public void setRegNo(String r){
        regNo = r;
        
    }
    
    public String getRegNo(){
        return regNo;
                
    }
    
    public void setDescription(String d){
        description =d;
        
    }
    
    public String getDescription(){
        return description;
        
    }
    
    public void setRunningCost(double c){
        runningCost = c;
        
    }
    
    public double getRunningCost(){
        return runningCost;
            
    }

    public void setAnnualInsurance(float i){
        annualInsurance = i;
        
    }  
    
    public float getAnnualInsurance(){
        return annualInsurance;
        
    }   
    
    public void setDepartment(String m){
        department = m;
    }
    
    public String getDepartment(){
        return department;
    }
            
  }

[Basskiddanny]

code for frmCars.java

package carcalculator;
import java.io.*;
import javax.swing.*;

/**
 *
 * @author  Daniel
 */

public class frmCars extends javax.swing.JPanel {
    
    ObjectOutputStream output;
    ObjectInputStream input;
    File file = new File(new File(getClass().getResource("dataFiles").getFile()),"cars.txt");
    
    
    /** Creates new form frmCars */
    public frmCars() {
        initComponents();
    }
    
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
    private void initComponents() {
        jFrame1 = new javax.swing.JFrame();
        txtRegNo = new javax.swing.JTextField();
        txtDescription = new javax.swing.JTextField();
        txtRunningCost = new javax.swing.JTextField();
        txtAnnualInsurance = new javax.swing.JTextField();
        txtDepartment = new javax.swing.JTextField();
        cmdNew = new javax.swing.JButton();
        cmdAdd = new javax.swing.JButton();
        cmdFirst = new javax.swing.JButton();
        cmdNext = new javax.swing.JButton();

        org.jdesktop.layout.GroupLayout jFrame1Layout = new org.jdesktop.layout.GroupLayout(jFrame1.getContentPane());
        jFrame1.getContentPane().setLayout(jFrame1Layout);
        jFrame1Layout.setHorizontalGroup(
            jFrame1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(0, 400, Short.MAX_VALUE)
        );
        jFrame1Layout.setVerticalGroup(
            jFrame1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(0, 300, Short.MAX_VALUE)
        );

        txtRegNo.setText("enterreg");

        txtDescription.setText("enterdesc");

        txtRunningCost.setText("enterrunningcost");

        txtAnnualInsurance.setText("enterinsurance");

        txtDepartment.setText("enterdepartment");

        cmdNew.setText("New");
        cmdNew.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                cmdNewActionPerformed(evt);
            }
        });

        cmdAdd.setText("Add");

        cmdFirst.setText("First");

        cmdNext.setText("Next");

        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(org.jdesktop.layout.GroupLayout.TRAILING, layout.createSequentialGroup()
                .addContainerGap(145, Short.MAX_VALUE)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
                    .add(layout.createSequentialGroup()
                        .add(cmdNew)
                        .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                        .add(cmdAdd)
                        .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                        .add(cmdFirst)
                        .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                        .add(cmdNext))
                    .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING, false)
                        .add(txtDescription)
                        .add(txtRunningCost)
                        .add(txtAnnualInsurance)
                        .add(txtRegNo, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 163, Short.MAX_VALUE)
                        .add(txtDepartment)))
                .add(25, 25, 25))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .add(35, 35, 35)
                .add(txtRegNo, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(txtDescription, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(txtRunningCost, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(txtAnnualInsurance, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(txtDepartment, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .add(23, 23, 23)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                    .add(cmdNew)
                    .add(cmdAdd)
                    .add(cmdFirst)
                    .add(cmdNext))
                .addContainerGap(100, Short.MAX_VALUE))
        );
    }// </editor-fold>

    private void cmdNewActionPerformed(java.awt.event.ActionEvent evt) {                                       
// TODO add your handling code here:
    try {
        output = new ObjectOutputStream(new FileOutputStream(file));
    }
    catch (IOException e){
        JOptionPane.showMessageDialog(this, "File Not Found!", "Error", JOptionPane.ERROR_MESSAGE);
    }
    }                                      
 /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                frmCars gui = new frmCars () ;
       gui.show(true);
            }
        });
    }   
    
    // Variables declaration - do not modify
    private javax.swing.JButton cmdAdd;
    private javax.swing.JButton cmdFirst;
    private javax.swing.JButton cmdNew;
    private javax.swing.JButton cmdNext;
    private javax.swing.JFrame jFrame1;
    private javax.swing.JTextField txtAnnualInsurance;
    private javax.swing.JTextField txtDepartment;
    private javax.swing.JTextField txtDescription;
    private javax.swing.JTextField txtRegNo;
    private javax.swing.JTextField txtRunningCost;
    // End of variables declaration
    
}

In the document frmCars.java the following lines were not present automatically in the file:

public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                frmCars gui = new frmCars () ;
       gui.show(true);
            }
        });
    }

But without them i was getting the error:

Class "carcalculator.frmCars" does not have a main method


By the way i am only a beginner when it comes to java, but i have been at this for hours and i really can't figure it out

Many Thanks,
Dan

[Basskiddanny]

Okay i've sorted it now. When i created the new form i selected JPanel Form instead of JFrame form! Whoops! lol.

Hopefully peopel won't make this silly mistake after reading this!