1172: Definition fl.events could not be found.

Question

I've tried putting in the simple code (into the 1st keyframe
of a layer) shown below but it gives me 2 "1172: Definition
fl.events could not be found." errors. I also get 1172 errors if i
try to import any of the other fl. classes.
Code:
import fl.events.*;
import flash.events.*;
var asCircle:MovieClip = new My_Circle();
asCircle.x = asCircle.y = 100;
addChild(asCircle);
var xVel:Number = 20;
addEventListener(Event.ENTER_FRAME, onLoop, false, o, true);
function onLoop(evt:Event):void {
asCircle.x += xVel;
If i comment out "import fl.events.*;" and the
"addEventListener(Event.ENTER_FRAME, onLoop, false, o, true);" it
does create the My_Circle at (100,100) so its not a problem with
that as far as I can tell. This also shows that the "import
flash.events.*;" statement works fine. I've also tried putting the
code into a .as file and accessing as the Document file but it just
gave the same errors.
I have trawled the net and can't find anything that works.
I've even tried changing the ActionScript 3.0 Classpath without any
success even though i set to read the right paths as described here
for the fl classes:
http://livedocs.adobe.com/flash/9.0/main/wwhelp/wwhimpl/common/html/wwhelp.htm?context=Liv eDocs_Parts&file=00000388.html
I can't understand why it won't work as the code is so
simple. The fact import statements don't work even though they come
up blue makes me think its an installation problem but i haven't
fiddled with any of the install settings and I have uninstalled and
reinstalled 3 times. I'm using a copy of Adobe Flash CS3
Professional trial version.
Any help would be greatly appreciated. It seems it should be
such a simple thing to fix but nothing seems to work.

Answer 1

I thought I needed to import fl.events.* or flash.events.* to
be able to use the addEventListener, turns out you don't need to.
I'm just learning ActionScript at the moment and trying to get my
head around it. I'm used to using languages where you need to
import classes to use methods from them (i.e. Java). I went through
all the video tutorials and stuff, obviously that doesn't seem to
have helped much in learning ActionScript 3.0.