_blank page open parent

I have a page that open a new window witn _blank target.
At this page I want to reload the parent window or even better to reload a div with ajax.
I tried this window.opener.reload() but did not work.
How can I do with?
I use cakephp with prototypejs

opener.reload() should work provided that the page that did the opening is still in that window. If there is something else in that window now then you can’t reference it any more.