Can I Combine ASP With External CSS?

I am trying to display a random background image for a webpage. I found this code to do it

<%
'Defines the number of background images you have
Const NUMBER_OF_IMAGES = 2

'Initiates the randomize function
Randomize

'Sets a variable: this will be used to hold the
'random generated value
Dim intImageNumber

'This is where we create the random number
intImageNumber = Int((NUMBER_OF_IMAGES * Rnd) + 1)
%>

Modify the body tag to accept the random number. In this case we are going
to place it within the image so as to facilitate the selection of a random
image. Code: