Turning off caching for loading a text file

Question

I'm new to AS3 and don't understand the properties setting
for URLRequest. I'm trying to turn caching off so when I reload the
text file, it always gets a fresh copy. I keep getting compiler
errors however with the useCache line. I'm not accessing the
properties correctly or something. When I take out that line it
works fine but always fetches the cached file.
My code is:
loadDoctorVariables();
function loadDoctorVariables() {
var requestJo:URLRequest = new URLRequest("
http://www.grxsolutions.com/gtslideshow3/"+doctorURL+".txt");
//requestJo.useCache(false);
requestJo.useCache = false;
var variables:URLLoader = new URLLoader();
variables.dataFormat = URLLoaderDataFormat.VARIABLES;
variables.addEventListener(Event.COMPLETE, completeHandler);
try
variables.load(requestJo);
catch (error:Error)
trace("Unable to load URL: " + error);
function completeHandler(event:Event):void {
var loader:URLLoader = URLLoader(event.target);
trace(loader.data.dayNames);
trace(loader.data.monthNames);
trace(loader.data);
trace(loader.data.saturationColor);
//saturationColor=10&hue=100&tint=255&bright=12&bgimage=ironman&slidesused=1,2,3,4,7,8,9, 10,11&voice=male1&alternateslides=7,doctorbob1,11,doctorbob2
}

Answer 1

append a random string to the URL, ie
var requestJo:URLRequest = new URLRequest("
http://www.grxsolutions.com/gtslideshow3"+doctorURL+".txt"+"?c="+Math.random());