Selenium TestNG

import org.testng.annotations.Test;

import org.testng.annotations.BeforeTest;

import org.testng.annotations.AfterTest;

import com.thoughtworks.selenium.DefaultSelenium;

public class testNgTest {

public static DefaultSelenium selenium;

 @Test

 public void verifyMaillogin() throws Exception{

              selenium.open("/");

            selenium.windowMaximize();

            selenium.type("id=f_id", "may397");

            selenium.type("id=f_pwd", "selenium");

            selenium.click("css=input.signin");

                        Thread.sleep(7000);

                        System.out.println("Hiiii");

                        selenium.click("link=Sign out");

 }

 @BeforeTest

  public void beforeTest() {

  selenium=new DefaultSelenium("localhost",4444,"*firefox","http://mail.in.com");

  selenium.start();

 }

 @AfterTest

  public void afterTest() {

  //selenium.stop();

 }

}