To include this FX in your document you need to put the the following in the HEAD section of your document

<!-- *** BEGIN CUT - Start Code *** -->
<!-- (* Another free JavaScript from *) -->
<SCRIPT LANGUAGE="javascript" SRC="javascript/JSFX_Layer.js"></SCRIPT>
<SCRIPT LANGUAGE="javascript" SRC="javascript/JSFX_Mouse.js"></SCRIPT>
<SCRIPT LANGUAGE="javascript" SRC="javascript/JSFX_Spring.js"></SCRIPT>
<SCRIPT LANGUAGE="javascript" TYPE="text/javascript">
function JSFX_StartEffects()
      JSFX.MakeSpring (10,"<font color='blue'>o</font>");
<!-- *** END CUT - End Code *** -->

Put the following in the BODY TAG of your document

<BODY onLoad="JSFX_StartEffects()">

Param1: 10 - Number of "Masses" in the mouse trailer.
Param2: "<font color='blue'>o</font>" - This is the "Mass". Use any valid HTML.
Advanced Customization...

Also See...
Using External ".js" Files
Combining Multiple Scripts.