Applying new leading value to textfield

I have a textfield that I’m using for both plain text (loadVariables) and XML. I need to be able to adjust the leading (space between lines of text) for the XML. Does anyone know of a way to change this value on the fly? Otherwise, I’m stuck using separate textfields and turning visibility on and off. That sucks. So far, I can’t find a way to even apply leading changes to XML. It only seems to work on embedded text. Btw, I’m using Flash MX 2004.

var myFormatter:TextFormat = new TextFormat();
myFormatter.leading = 10;
this.createTextField("message_txt", 1, 100, 100, 380, 130);
message_txt.multiline = true;
message_txt.wordWrap = true;
message_txt.border = true;
message_txt.html = true;
message_txt.text = "This is my first textfield object test - leading is set to 10. This is my first textfield object test - leading is set to 10.";
//loadNewsXML(2006); // Leading doesn't apply to XML
message_txt.setTextFormat(myFormatter);