Be sure that you export the .swf to be viewed only with the Flash 6 player.
You can load more than one variable from the text file at a time by separating
them with an & as shown below: myFirstVariable=something&mySecondVariable=more&myThirdVariable=even
more
You can use less frames in the timeline. I added more frames just to spread
it out and make it easier to read. If you remove frames remember to change the
actions on the buttons which point to the keyframes (5, 10, 15).