loadVars Problem

Hello again-
Im trying to load a variable from a text file with loadVars
The txt file has this -

num = 10

The flash looks like this

var load_lv = new LoadVars();
load_lv.load("tmbnum.txt");
load_lv.onLoad = loadTextVariables;
function loadTextVariables(success){
	if(success){ 
		trace(this.num);
	} 
}
thumbNum = num;
trace(thumbNum);

The “trace(this.num)” shows the number 10 like it should.
The “trace(thumbNum)” comes back undefined (should show 10).

What am I doing wrong?