How to call RSS

for this feed:

how do i call this in my Flash file…for a simple local xml file- the code works and now that im trying to connect it with an external xml file… does not work becuase the structure is different…

how do i populate a value from the above RSS into my news_txt textfield:

_root.thetitle = this.firstChild.firstChild.childNodes[0].childNodes[1].firstChild.nodeValue;
news_txt.htmlText = _root.thetitle;