1021: Duplicate function definition I am lost... please advise

Question

I am obviously new to as3... So I have 3 buttons (all in the same scene) that each need to go to a different scene. I put the script's on the same frame. Here is the script's:
btn_pg.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);function mouseDownHandler(event:MouseEvent):void {
gotoAndStop(1, "photo_gallery");
btn_vg.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);function mouseDownHandler(event:MouseEvent):void {
gotoAndStop(1, "photo_gallery");
This is the error message it gives me:
home_1, Layer 'actions', Frame 1, Line 8 1021: Duplicate function definition.
What do you have to do to use the same function for different buttons to get to different scenes?
Thank you for any consideration and help,
Thomas

Answer 1

I tried to ad another button to that same code and it does not give an error but when i publish it doesn't do anything...
This is the code after I added:
btn_pg.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
btn_vg.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
function mouseDownHandler(event:MouseEvent):void
var nameOfButton:String = event.currentTarget.name;
if (nameOfButton == "btn_pg")
  gotoAndStop(1, "photo_gallery");
else if (nameOfButton=="btn_vg")
  gotoAndStop(1, "video_gallery");
else if (nameOfButton=="btn_b")
  gotoAndStop(1, "blog");
Can you not have an infinite amount of buttons with this code?
Thanks again
Thomas