Dynamically Loaded Text

I am trying to load text from an external .txt file but I keep geting an error message.

This is my code:

 loadText = new loadVars();
loadText.load("bio.txt");
//creating the loadVarsText function
loadText.onLoad = function() {
  scroller.text = this.biotext;
}; 

This is the error I keep getting:

The identifier ‘loadVars’ will not resolve to built-in object ‘LoadVars’ at runtime.
loadText = new loadVars();

Thanks alot.