To make available yet another file "file.js" you need to make a reference to the file in your HTML page. For example if your start page called "home.html" edit content of the <head> tag and add new <script> tag...
<head>
...
<script src="your_path/file.js" type="text/javascript"></script>
<script src="your_path/home.js" type="text/javascript"></script>
...
</head>
In this case functions from "file.js" file will be available in "home.js" file.
Hope this helps.
Slava Ivanov
