You haven't said if these pages are in separate windows, tabs, frames or whatever. I'm not sure about tabs but, generally they would act like separate windows. With frames, as long as you are all on the same domain, you can target the frame document various ways, depending upon where you are doing it from. With windows, the easiest way is if at least one of them have been opened via javascript:
Code:
var mywin=window.open('some_page.htm');
so that it could be referenced by its variable name. Care must also be taken to use mywin.document or mywin.window, depending upon if you are accessing the document or the window.
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