NullPointerError Blog

import javax.swing.*; import java.awt.*; import java.awt.event.*; class form1 extends JFrame { JLabel l1; form1() { Icon icon2=new ImageIcon("4.JPG"); l2=new JLabel(icon2); l2.setBounds(0,0,600,500); cn.add(l2); setBounds(250,100,600,100); cn.setBackground(Color.BLACK); setSize(600,500); setVisible(true); addWindowListener(this); } public static void main(String arg[]) { new form1(); } }

import javax.swing.*; import java.awt.*; import java.awt.event.*; public class form2 extends JFrame implements ActionListener { JLabel l1,l2,l3; JTextField t1,t2; JMenuBar menubar; JMenu menu1,menu2,menu3,menu4,menu5,menu6,menu7; JMenuItem mt1,mt2,mt3,mt4,mt5,mt6,mt7,mt8,mt9,mt10,mt11,mt12; form2() { Container cn=getContentPane(); menubar=new JMenuBar(); //menu "Add" added menu1=new JMenu("Add Record"); mt1=new JMenuItem("Customer Record"); mt2=new JMenuItem("Dealer Record"); menu1.add(mt1); menu1.add(mt2); menubar.add(menu1); setJMenuBar(menubar); //menu "Search" added menu2=new JMenu("Search Record"); mt3=new JMenuItem("Customer Search"); mt4=new JMenuItem("Dealer Search"); menu2.add(mt3); menu2.add(mt4); menubar.add(menu2); setJMenuBar(menubar); //menu "Update" added menu3=new JMenu("Update Record"); mt5=new JMenuItem("Customer Up...

Imports System.Data.OleDb Imports System.Data Public Class Form1 Dim CON As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=.\db5.mdb")//Database Path Dim DA As New OleDbDataAdapter Dim DS As New DataSet, I As Integer = 0, J As Integer = 0 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click CON.Open() DA.InsertCommand = New OleDbCommand DA.InsertCommand.CommandText = "INSERT INTO Table1 VALUES('" & Val(TextBox1.Text) & "','" & TextBox2.Text & "')" DA.InsertCommand.CommandType = CommandType.Text DA.InsertCommand.Connection = CON DA.InsertCommand.ExecuteNonQuery().ToString() End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click DA.SelectCommand = New OleDbCommand DA.SelectCommand.CommandText = ...