javascript - Detect opened windows/tabs in Firefox -

I have an application window that displays a button, when you click on the button, opens with a new tab window is. Open Javascript function and later I have to find out if that link has been opened, and if it is, then I have to close that window. What can this be done in Firefox?

Thank you.

window. The Open () function returns a window object Just close () on it:

  var childwindow = window.open (....); ... baby window.close ();