HI, i'm getting a nullpointer exception.help me.it's urgent import java.awt.*;

import javax.swing.*;
//import 
public class Employee
{
final int WIDTH = 450;
final int HEIGHT = 400;
JFrame f;
//MenuBar mb;
//Menu m;
//JButton b1,b2,b3,b4,b5,b6,b7;
JPanel p,p1,p2,p3,p4,p5,p6,p7,p8,p9;
JLabel l1,l2,l3,l4,l5,l6,l7,l8,l9;
JTextField t1,t2,t3,t4,t5;
JComboBox c1,c2,c3;
FlowLayout leftLayout;
String s1[]={"1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20","21","22","23","24","25","26","27","28","29","30","31"};
String s2[]={"1","2","3","4","5","6","7","8","9","10","11","12"};
String s[]={"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};


Employee()
 {
   leftLayout = new FlowLayout(FlowLayout.LEFT);
   //p.setLayout(new BoxLayout(p,BoxLayout.Y_AXIS)); 
   /*p.add(b1);
   p.add(b2);
   p.add(b3);
   p.add(b4);
   p.add(b5);
   p.add(b6);
   p.add(b7);
   f.add(p);*/

   p1= new JPanel();
   p1.setLayout(new FlowLayout(FlowLayout.CENTER));
   l1= new JLabel("Employee Management System");
   p1.add(l1);
   f.add(p1);

f.setLayout(new GridLayout(10,1));
//f.setSize(WIDTH,HEIGHT);
f.setBackground(Color.BLUE);
f.setResizable(true);




   p5=new JPanel();
   l5=new JLabel("Personal Information");
   p5.setLayout(leftLayout);
   p5.add(l5);
   f.add(p5);   
   p2=new JPanel();  
   p2.setLayout(leftLayout);
   l2 = new JLabel(" First Name       ");
   t1 = new JTextField(25);
   f.add(p2);
   p2.add(l2);
   p2.add(t1);


   p3= new JPanel();
   p3.setLayout(leftLayout);
   l3 = new JLabel(" Second Name ");
   t2 = new JTextField(25);
   f.add(p3);
   p3.add(l3);
   p3.add(t2);

   p4= new JPanel();
   p4.setLayout(leftLayout);
   l4 = new JLabel(" Family Name   ");
   t3 = new JTextField(25);
   f.add(p4);
   p4.add(l4);
   p4.add(t3);


   p6=new JPanel();
   l6=new JLabel("Date of Birth");
   p6.setLayout(leftLayout);
   p6.add(l6);
   f.add(p6);


   p7= new JPanel();
   p7.setLayout(leftLayout);
   l7 = new JLabel("   Day of Birth   ");
   c1=new JComboBox(s1);
   p7.add(l7);
   p7.add(c1);   
   f.add(p7);


   p8= new JPanel();
   p8.setLayout(leftLayout);
   l8 = new JLabel(" Month of Birth   ");
   c2=new JComboBox(s2);
   p8.add(l8);
   p8.add(c2);
   f.add(p8);


   p9= new JPanel();
   p9.setLayout(leftLayout);
   l9 = new JLabel("   Year of Birth   ");
   c3=new JComboBox(s);
   p9.add(l9);
   p9.add(c3);
   f.add(p9);


   f.setVisible(true);
   f.setSize(170,170);
   f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 }

public static void main(String []args) 
 {
  Employee a=new Employee();
// a.launchFrame(); 
 }
}