I need a window with transparent view to be in the top of any screen.
Any one can help?

It’s not possible. That’s not how the player/AIR works.
The player has 3 layers, down is video layer, middle is stage3D and on top the classic display list. You cannot change that order. Check Adobe website for details.
In AIR you can have os’s windows with different chromes and use transparency, that you eventually could render on top of other os window, but it is unlikely what you’re after…

Thanks Fabrice for replying, i will use opengl to do that.

well, you can, but you will hit similar issues, not to mention it will crawl in many browsers. Tho, the last time I tried this is a while back, it might have changed. Good luck!