Switching frame using WebDriver

public class paytm {
WebDriver driver= new FirefoxDriver();
  @Test
  public void f() {
 driver.findElement(By.xpath(".//*[@id='logo-bar']/div[1]/ul/li[1]/a")).click();
 driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
 driver.switchTo().frame(1);
 driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
 driver.findElement(By.xpath("//*[@id='loginForm']/div[2]/input")).sendKeys("abc@gmail.com");
      
  }
  @BeforeTest
  public void beforeTest() {
 driver.get("http://paytm.com/");
 driver.manage().window().maximize();

  }

  @AfterTest
  public void afterTest() {
 driver.close();
  }

}