How to handle pop up windows with blank id in selenium webdriver?

Question

I want to automate the code for submit resume page in my application. The page consist of a section to add in the qualification details which further opens a window to add the same. The problem is the window that is opening has blank id and on automating the same i get session expired message in it, which otherwise works fine when i access it through selenium ide or manually. Attaching the code for reference.

My code is as below:-

w.get("https://www.hrmantra.com/LetsLead/18_Recruitment/SubmittResume.aspx?cn=L‌​etsLead");
String parentHandle = w.getWindowHandle();
w.findElement(By.xpath("//.//*[@id='lbAddQualification']")).click();
for (String winHandle: w.getWindowHandles()) {
    w.switchTo().window(winHandle);
    e = new Select(w.findElement(By.xpath("//.//*[@id='lstlist']")));
    e.selectByVisibleText("A Level DOEACC");
    w.findElement(By.xpath("//.//*[@id='Btnconadd']")).click();
    w.findElement(By.id("BtnAdd")).click();
}
w.switchTo().window(parentHandle);

Answer 1

After switch you need to right code outside the loop like this:

static WebDriver driver=null;
public static void main(String[] args) {
    driver = new FirefoxDriver();
    driver.get("https://www.hrmantra.com/LetsLead/18_Recruitment/SubmittResume.aspx?cn=L‌​etsLead");
    driver.manage().window().maximize();
    driver.manage().timeouts().implicitlyWait(40, TimeUnit.SECONDS);


    String mainwindow=driver.getWindowHandle();
    driver.findElement(By.xpath("//.//*[@id='lbAddQualification']")).click();

    for(String winHandle :driver.getWindowHandles()){
        driver.switchTo().window(winHandle);
    }
    // Here right your code which you want to perform on pop-up
    driver.close();
    // Back to main window
    driver.switchTo().window(mainwindow);