Handling Pop up in Selenium2

public class closeopen {
    public static void main(String[] args) {
       
         WebDriver driver = new FirefoxDriver();
         driver.get("http://www.javascripter.net/faq/alert.htm");
         driver.findElement(By.xpath("html/body/p[1]/table/tbody/tr/td[1]/form/input")).click();
         Alert alert = driver.switchTo().alert();
         alert.accept();
}
}

enjoy