Is there a cross-browser compatible way to post a form in one tab of the browser to another (which I know is open and is of the same domain)?
I tried window.name='some_name'; and target='some_name' on the form, but this does not seem to work. Am I missing something?
There is no standard to how tabs are handled via javascript, so you are out of luck.
Most browsers these day also make sure each tab is segregated/partitioned from others, as much as possible, so this is unlikely to change in the recent future.
The closest you can get to posting to a different page is to use AJAX, or possibly using frames.