Simple XML text box

Ok, i’m sure this topic has been asked countless times. But I can’t find a clear answer. … I know nothing very little about actionscript and nothing at all about XML.
The thing is I have an empty dynamic text box (instance name: “update”), and want to be able to load simple text from an XML file. What action script do I need, and what XML tags do I need? I know it’s a stupid question. It would at least help if you could point to a thread that has addressed this issue (in “simple” terms) thanks!!