HTML5&JS-Game-1 Large JS Into Separate JS Files?

Hi,

I am a C++ game programmer who attempted to make an HTML5/JS game.

Game turned out great (except for some performance issues on old computers).

Although the game is good, I am terribly embarrassed about the source.
Source is HTML5/JavaScript and its one giant, ugly, and confusing HTML file.

I've been researching on Google how to split the 1 large HTML file
into smaller separate *.js files but can not get it working.


Here is the URL link to the game's folder on my web site:
http://16bitsoft.com/T-Crisis3AI--HTML5/

I've tried to split the one HTML file into smaller separate *.js files.
Had a "Logic.js" file with all logic global variables and functions in it
and I loaded the "Logic.js" file (I think) into main HTML file
but the main HTML file can't locate the logic variables and functions???

If your a Jedi Master Ninja Assassin HTML5/JavaScript coder
then please try to help!

Thanks!

JeZ+Lee
16BitSoft
Video Game Design Studio
www.16BitSoft.com

Here is screenshots of the game: