This is an example of how to create a random number in Classic ASP in order to append to a swf file so that the browser does not cache the swf file.
<% Dim SwfRndNum Randomize SwfRndNum = Rnd %>
You can then add it to your swf embed code as follow, bear in mind that I am only showing the snippet around the swf file name and not the entire embed code.
mySwfFile.swf?a=<% Response.Write SwfRndNum %>