window.open open new window?

when ever i use

 window.location.href=//some url 

it always open a new window, this only happens when the parent window is an dialog box.

what is wrong?

 window.open("http://asdf.com", "_self"); 

as suggested on this thread window.location.href opens another window but it is still not working

Answers:

Parent window

window.open("http://asdf.com", "window_name","location=1,status=1,scrollbars=1,resizable=no,width=650,height=650");

code in a parent window to open new

window.open('http://www.google.com', 'window_name', '_self')