Translation:There is not any kind of flower in the window.
Yes, it's correct. If you do a Google image search for "flowers in the window" you will see a lot of pictures of exactly what it means.
:-)) same results with AT ! Maybe both have the same meaning in English.
For me, "in the window" is more specific and means just about exactly what you are seeing in those pictures.
"At the window" is less specific. It could mean the same as "in the window" or it could mean just somewhere near the window. For example, right now I could go stand at the window and look outside. It would be very odd for me to stand in the window, though.
If you stand at the window, then someone outside might see you in the window. :) Maybe "in the window" is more for the perspective of people who are looking in? So if you stand in the window, the idea is that you are putting yourself in a position to be seen by people from the outside.
I guess both are expressed by "ablakban"?
By the way, how are you able to write some your comment in italics?
As an english native i find that in the window usually means you are seeing from the other side "how much is that doggy in the window?" At the window is usually used if you are on the same side as the object. "Look at those flowers at the window"
Could it be translated "There are no flowers in the window"? "No airplanes fly there" is translated as "Nem repül oda semmilyen repülőgép", therefore it should be possible.
I agree, because I cannot imagine any English speaker using the sentence as translated.
From the outside Brits would usually say "there are no flowers in the window, but from the inside "there are no flowers on the window-sill". Unfortunately, with the translation, it seems to be trying to say "There are no flowers of any kind in the window" or "there is no flower of any kind".