Add A Target To This AS3 URL Script?

Seems like AS3 is more about writing code than AS2.I would normally write the code on the button:

Code:

on(release){
getURL("http://sample.com". "_blank");
}

Instead in AS3 I have to do this for a button action:

Code:

myButton.addEventListener(MouseEvent.CLICK, myButtonFunction);
function myButtonFunction(event: MouseEvent) {
var request:URLRequest = new URLRequest("http://www.sample.com");
navigateToURL(request);
}

How do I add the _blank target function to this AS3 code. I am still trying to get use to this AS3 concept.