Flash :: Link In Keeps Opening In New Window

I have l a flash file in my pages that links to other pages within my web site but when clicked they automatically open in another window. How can I link them without opening a new window as would happen with a normal web page  link?
 
Here is my current Action Script code: index.addEventListener(MouseEvent.CLICK,indexbuttondown);
 
function indexbuttondown(event:MouseEvent):void {
var bbcURL:URLRequest = new URLRequest("index.html");
navigateToURL(bbcURL);
}