Removing titlebar

I want to remove titlebar from some mozilla widows.
I use the window.open feature titlebar=no but it doesn't
work. I think that it may have some ways by KDE or Gnome
API or either by some access rights to be granted in Linux in order
to make this working and remove the titlebar.
Any Idea?
Thank you

I doubt that's possible with JavaScript. That's a window manager's function.