How to handle Multiple windows ?

package SeleniumMakeItEasy;

import java.util.Iterator;
import java.util.concurrent.TimeUnit;

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;

public class Naukari {
    public static void main(String[] args) {
        WebDriver driver = new FirefoxDriver();
        driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
        driver.get("http://www.naukri.com/");
        Iterator<String> in = driver.getWindowHandles().iterator();
        String mainPage = in.next();
        String child1 = in.next();
        String child2 = in.next();
        driver.switchTo().window(child1); //switch control to 1st child window
        //here you can perform any operation on child1 window if u want
        driver.close(); //close 1st child window
        driver.switchTo().window(child2); //switch control to 2nd child window
        //here you can perform any operation on child2 window if u want
        driver.close(); //close 2nd child window
        driver.switchTo().window(mainPage); //switch control to main page of naukari.com
    }
}