I am automating a webpage using Selenium Webdriver. I am not able to click a button a modal pop up window using simple element locator method.
Example:
- open www.walmart.com
 - enter tv in the search box.
 - select some tv and click "Add to Cart"
 - Now a pop up window comes where "Checkout" button is located. I need to click on this "checkout" button.
 
I tried switchTo() windowhandle, I tried switchTo() frame but nothing worked.