submit form to new tab in current pop-up

A link in the main browser开发者_C百科 window opens up a report in a pop-up window using window.open(). On this report is a form to create a second report.

I want this form to submit to a new tab in the same window. But in Firefox it opens a new tab in the main browser window and in IE8 it opens in a new full-size browser window.

Can I force it to submit to a new tab in both?

thanks

Derek