Hey there!
You're almost there -- there are just a couple small things that need adjustment in order to get this script up and running.
First, your variable name does not need quotes -- Flash, when it inputs the information, interprets the quotes as part of the variable value that you're passing. So the correct code in your flat file should be:
The second thing is that the targeting in your function is off. The code "loadMovie(movieData.var1, 0);" is pretty much the exact thing as "this.loadMovie(movieData.var1,0);". The problem is that in this situation, "this" refers to your function, not the root movie (which is where I'm assuming you want to load the movie). All you need to do is be more specific as to where you want to load the movie. So this code works:
movieData = new LoadVars();
movieData.onLoad = getMovieData;
movieData.load("variables.txt");
var MAIN_ROOT = this;
function getMovieData()
{
MAIN_ROOT.loadMovie(movieData.var1);
}
All I did was create a variable "MAIN_ROOT" and make that variable point to the movie clip which houses the function.
Let me know if you have any troubles with the code or any additional questions!
Best,
--eric
PS - For future projects, and particularly if you move on up to AS3, you may want to keep your variables inside an XML document instead of a flat text file. AS3 traverses XML really easily and it's easier to keep track of multiple variables in an XML document (large flat files can get unwieldy very quickly).