1.i have folder "1" that contains some images
2.the script will take one random image from "1", and put it on another one, named "background.png"
3.the final image will be saved on folder "2"
4.script will take the last image saved on "2" and will show it on screen...

I know just html and css....

I don't know how to do that, i don't know what language do i need... i think that i need some php and js...

I don't want to use db.

Who can help me with that?