Sometimes you want to do some user interaction without cluttering up your main window. One easy way to do this is by opening up a new window.
Here's how you can do it.
You can also change form elements and other data by referring to the first page as window.opener in the DOM. If you wanted to open a new page in the main window that didn't happen to have the same base URL, then you'd use window.opener.location.href instead of window.opener.location.pathname. Best of luck, and I hope that helps.