When I run this below codes, the public static void main(String args[]) { is underlined red.How to remove the red underlined to make the program run-in java.

The codes are:

import javax.swing.JOptionPane; import javax.swing.table.DefaultTableModel;

public class NewJFrame extends javax.swing.JFrame {

/** * Creates new form NewJFrame */ public NewJFrame() { 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. */ @SuppressWarnings("unchecked") // private void initComponents() {

jLabel1 = new javax.swing.JLabel(); jLabel2 = new javax.swing.JLabel(); jLabel3 = new javax.swing.JLabel(); txtname = new javax.swing.JTextField(); txtsurname = new javax.swing.JTextField(); txtage = new javax.swing.JTextField(); btnadd = new javax.swing.JButton(); jScrollPane1 = new javax.swing.JScrollPane(); jTable1 = new javax.swing.JTable();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

jLabel1.setText("Name");

jLabel2.setText("Surname");

jLabel3.setText("Age");

btnadd.setText("Import"); btnadd.setActionCommand("IMPORT"); btnadd.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { btnaddActionPerformed(evt); } });

jTable1.setModel(new javax.swing.table.DefaultTableModel( new Object [][] { {null, null, null}, {null, null, null}, {null, null, null}, {null, null, null} }, new String [] { "Name", "Surname", "Age" } )); jScrollPane1.setViewportView(jTable1);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); getContentPane().setLayout(layout); layout.setHorizontalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(73, 73, 73) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(btnadd) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jLabel1) .addComponent(jLabel2) .addComponent(jLabel3)) .addGap(41, 41, 41) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false) .addComponent(txtname) .addComponent(txtsurname) .addComponent(txtage, javax.swing.GroupLayout.DEFAULT_SIZE, 143, Short.MAX_VALUE)))) .addContainerGap(143, Short.MAX_VALUE)) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(53, 53, 53) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel1) .addComponent(txtname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGap(18, 18, 18) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel2) .addComponent(txtsurname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGap(18, 18, 18) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel3) .addComponent(txtage, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGap(33, 33, 33) .addComponent(btnadd) .addGap(43, 43, 43) .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 151, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(268, Short.MAX_VALUE)) );

pack(); }//

private void btnaddActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: if(txtname.getText().equals("")||txtsurname.getText().equals("")||txtage.getText().equals("")){ JOptionPane.showMessageDialog(this, "Please enter all data"); }else{ String data[]= {txtname.getText(),txtsurname.getText(), txtage.getText() }; DefaultTableModel tblModel= (DefaultTableModel)jTable1.getModel(); tblModel.addRow(data); JOptionPane.showMessageDialog(this, "Data added successfully"); txtname.setText(""); txtsurname.setText(""); txtage.setText(""); }

/** * @param args the command line arguments */ public static void main(String args[]) { /* Set the Nimbus look and feel */ // /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */ try { for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) { if ("Nimbus".equals(info.getName())) { javax.swing.UIManager.setLookAndFeel(info.getClassName()); break; } } } catch (ClassNotFoundException ex) { java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (InstantiationException ex) { java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (IllegalAccessException ex) { java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (javax.swing.UnsupportedLookAndFeelException ex) { java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } //

/* Create and display the form */ java.awt.EventQueue.invokeLater(new Runnable() { public void run() { new NewJFrame().setVisible(true); } }); }

// Variables declaration - do not modify private javax.swing.JButton btnadd; private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; private javax.swing.JLabel jLabel3; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JTable jTable1; private javax.swing.JTextField txtage; private javax.swing.JTextField txtname; private javax.swing.JTextField txtsurname; // End of variables declaration }