Button Problems

I need some help here.

This is my code:


stop();
about_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler1);
function mouseDownHandler1(event:MouseEvent):void {
    gotoAndStop(2);
}
port_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler2);
function mouseDownHandler2(event:MouseEvent):void {
    gotoAndStop(3);
}
serv_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler3);
function mouseDownHandler3(event:MouseEvent):void {
 gotoAndStop(4);
}

And it comes up wth these errors:


1021: Duplicate function definition.  function mouseDownHandler1(event:MouseEvent):void {


1021: Duplicate function definition.   function mouseDownHandler2(event:MouseEvent):void {

1021: Duplicate function definition.  function mouseDownHandler3(event:MouseEvent):void {

Also, it doesn’t “stop();” it just keeps looping. Any help would be appreciated.