Dynamic Text - Adding mulitple lines

Hi. I’m trying to write an actionscript that will load additional lines within a dynamic text block (i.e. new text that loads below text that already sits within the text block). Here is where I am so far (a script from a kirupa tutorial):

::::::::::

on (release) {
loadText = new loadVars();
loadText.load(“sp_001.txt”);
loadText.onLoad = function(doit) {
if (doit) {
textBox.html = true;
textBox.htmlText = this.spText add existing;
}
};
}

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Logically, I know what to do but am lacking the skills to script it. It seems I need to define how long I want the list and then if/else. Any help is appreciated. Thanks.