3D background named starry night

That's it .My starry background of website.It can move according to the scale of browser,looks like 3D effectiveness.

I make the stars to 3 layers using ps6, storing them as three .png files. First layer named pg1.png, which is the stars with black background.Second layer named pg2.png, which is just stars for transparent background. And third layer named pg3.png, the same as layer second.

body is for first layer.midground div is for second layer. foreground div is for third layer.

Here is the code:

html

css

 it doesn't work on IE6 and below browsers .