Post back parent page from a pop up page

Hi,
I have a GridView control and I update a TemplateField with a HyperLink from code behind. The HyperLink links to a pop up window (new aspx page).
After I click  the "save" button on the pop up window, I would like the parent page to refresh (by clicking  the "refresh" button)
The problem is that the window.opener is empty.
Is there any other way to trigger a post back of the parent page?