what have you done so far? do you really want to open two windows or do you want to update the location-url of two different frames or already opened windows? ... please explain your requirement in more detail ...
give the frames a name or refer with the frames-collection to the corresponding frame and call a javascript function that sets:
[CODE=javascript]frame_ref.locat ion.href = 'url';[/CODE]
for every wished frame ... post what you have so far in case you have problems with the correct implementation ...
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