Why is the address bar not editable?

Sometimes in website开发者_StackOverflow社区s when you click on some link a new browser windows appears where there's no back button and address bar is not editable,it's locked (greyed out) so you can't change the URL. Just a box containing some information or text boxes to enter data. I would like to know why. Is this because of some security issues or is there something else?

You are right - it has something to do with security, and in particular, preventing spoofing attempts.

The address bar is usually present in the popup windows of many browsers to indicate which page is being displayed. This way, the user is aware of their current location and will be able to tell if the popup is navigating to an illegitimate website.

The address bar is disabled as a cue to the user that they should not be navigating to a different page within the new window, but should continue their browsing experience by closing the popup and returning to the main window.

Please see this Mozilla ticket - https://bugzilla.mozilla.org/show_bug.cgi?id=470051 - and especially Nochum Sossonko's comment for reference.