public static boolean isAlertPresent(WebDriver driver) {

　　try {
　　driver.switchTo().alert();
　　　　return true;
　　} catch (NoAlertPresentException ex) {
　　　　return false;
　　}
}

/**
* Sometimes will pop up an alert window, you can use this method to close
* it.
*/
public static void closeAlert(WebDriver driver, boolean acceptAlert) {
　　Alert alert = driver.switchTo().alert();
　　if (acceptAlert) {
　　　　alert.accept();
　　} else {
　　　　alert.dismiss();
　　}
}