Flash Drop Downs - Please Help!

Question

THANKS in advance for the help you can provide.
I am attempting to build a flash drop down navigation bar and I followed the Tutvid video tutorial on YouTube, which launched successfully - it looks wonderful!
However, when I wanted to add additional drop down menus for other buttons, the video has a big gap in information for the beginner (me).
To speak the same language, the video is at this address: http://www.youtube.com/watch?v=LC7BaZCForE
Action Script sequences to scroll to are the following:
1. Movie where drop downs are created on timeline with action script: 29:13
2. Action Script content for Hit Area: 29.52
3. Root Layer action script: 32:33
I assumed that I should be adding my additional menu drop downs on the same timeline window as the first.  I added new layers for the menus and frames, but I thought I should write the action script for the new menus on the same action script layer as the first.  I added action script 10 frames from the first menu, so the next grouping began at frame 20 and ended at frame 30.
Adding the second menu (I want more but stopped when I tested) resulted in the two menus alternately blinking on and off so a repeating movie kicks in and no "over" and "out" functions for the menu are recognized.
I'll now paste in my code for corresponding segments from his video so maybe you can show me where I need to change my coding to make it all work.  Apparently my function definition needs to change, but I have no clue what that means or how it needs to be different.  Before I paste, however, let me share the error that pops up:
Location: Symbol 'mcDropDowns', Layer AS MugCup', Frame 20, Line 4
Description: 1021: Duplicate function definition.
Okay, here's my coding:
1.
Frame 1
stop();
clicker_mc.visible = false;
2.
Frame 10
stop ();
mugFrame_btn.addEventListener(MouseEvent.MOUSE_OVER, goBackF);
function goBackF(event:MouseEvent):void{
gotoAndStop(1);
Frame 20
stop ();
tableFrame_btn.addEventListener(MouseEvent.MOUSE_OVER, goBackF);
function goBackF(event:MouseEvent):void{
gotoAndStop(1);
3.
var navBtnGlow:GlowFilter = new GlowFilter(0x425616, 0.75, 0, 15, 1, 2, true, false);
navBar_mc.addEventListener(MouseEvent.MOUSE_OVER, navOverF);
navBar_mc.addEventListener(MouseEvent.MOUSE_OUT, navOutF);
function navOverF(event:MouseEvent):void{
event.target.filters = [navBtnGlow];
navBar_mc.setChildIndex(event.target as MovieClip, 1);
dropMenus_mc.gotoAndStop(navBar_mc.getChildAt(1).name);
trace("We are Rolled Over..." + navBar_mc.getChildAt (1).name)
function navOutF(event:MouseEvent):void{
event.target.filters = [];         
navBar_mc.addEventListener(MouseEvent.MOUSE_OVER, navOverF);
navBar_mc.addEventListener(MouseEvent.MOUSE_OUT, navOutF);
Please know that I realize this will take a few moments for you to compare my code to what's on the video.  Know that you will be doing me a TREMENDOUS favor by helping me to understand the theory behind replicating this step.
I look forward to hearing from you - THANKS!

Answer 1

Ah, no... I tested it further, and found that the script I
posted above is not causing the problem. This puts me even further
back than before... I truly have absolutely no idea what part of
the applet is malfunctioning now.
If there is any sort of list of known reasons for the flash
player to crash... actionscript or animation... I would greatly
appreciate seeing it.
Sorry if I'm failing to provide enough information about my
problem...