Prevent local file from caching when testing

1

How do you prevent a local file from caching when testing? Eg, on the web its easy…

var request:URLRequest = new URLRequest("…/flash/battleTanks.swf?" + Rand);

Windows throws a url not found with anything I try…

var request:URLRequest = new URLRequest("…/battleTanks.swf*");
var request:URLRequest = new URLRequest("…/battleTanks.swf?" + Rand);