[jQuery] Accessing Another Window

[Steve @ MFB]

Looking for information on how to access an opened window via:

$("newwindow.#tabnav").tabsAdd('#new-tab', 'Customer #4');

Where newwindow is the name of a variable that holds window.open.

I have a function that checks to see if the window is open, and if it
is, opens a tab (HTML) within that window.  I just need to know how to
access it via JQuery.  A link or explanation would suffice.

Thanks