Offline cache solution

I used this site’s tutorial on the loading movies with a unique identifier to avoid cache problems, but it doesn’t work when I go to test the movie in flash. Does it only work on the internet, or am I doing something wrong?

This is the code I have:

_global.uniquenum = Math.round(Math.random()*10000);

And then later on:

loadMovieNum(“home.swf?uniq=” + uniquenum , 1);

I even get the error:

Error opening URL “file:///(yadayadayada/home.swf?uniq=9043”

Anyone got any suggestions? Thanks