I have a page of rows of dynamic data... the user can click on a link for each entry... that allows them to open a popup window... add / edit or delete some sub-entries for each entry.

When they close the popup window, how can I get the background page to refresh and show the updated data... without pressing the refresh button...

a) could I get the page to refresh automatically every 30 seconds ?
b) could I get the popup to switch focus to the window that opened the popup and then refresh that page ?

Any tips ideas would be v.appreciated...

Cheers