634067 - Cannot create pop under with javascript

Status: RESOLVED WONTFIX

(Firefox :: General, defect)

Description

[gavinxyang]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/4.0

Looks like I cannot implement a pop under in firefox 4.0. All the pop under becomes pop up. following is my code:
 
window.open(url, "PopUnder", "toolbar=yes,dependent=no,top=0",false).blur();
window.focus();

Is firefox 4.0 needs new javascript to enable it or firefox doesn't allow that, how can I implement pop under

Reproducible: Always

Steps to Reproduce:
1.open page with my java script

Actual Results:  
It should be pop under, but it is pop up.

Expected Results:  
pop under

Comment 1

[Matthias Versen [:Matti]]

popunders are something that the web doesn't like and we blocked it with bug 369306